year 12 biology experiments

Top 30 Biology Experiments for High-School

The field of biology offers a wide range of fascinating experiments that can deepen our understanding of the living world around us. From studying the behavior of cells to investigating the intricacies of ecosystems, biologists use a variety of methods to uncover the secrets of life.

We’ve compiled a captivating list of 30 biology experiments that are both educational and fun and also suitable for a wide range of ages.

These hands-on educational activities will not only deepen your appreciation for the intricacies of life but also fuel your curiosity and passion for scientific exploration.

So, roll up your sleeves, gather your lab equipment, and prepare to embark on an exciting adventure through the fascinating world of biology-based science experiments!

1. Grow a Butterfly

Students can gain knowledge about the various phases of development, from the egg to the larva to the pupa to the adult butterfly, by studying and taking care of a butterfly during its whole life cycle. This offers students a special chance to learn about the insect life cycle and the metamorphosis process.

Learn more: Elemental Science

2. Dissecting a Flower

Dissecting a flower can aid students in honing their analytical and observational skills. This may also aid in their comprehension of how a flower’s various components interact to facilitate reproduction, which is the flower’s main objective.

Learn More: How to Dissect a Flower

3. Extracting a DNA

The extraction of DNA is an excellent experiment for high school students to gain a better understanding of the principles of molecular biology and genetics. This experiment  helps students to understand the importance of DNA in research and its applications in various fields, such as medicine, biotechnology, and forensics.

Learn more: Extracting DNA

4. Looking at Fingerprints

Exploring fingerprints can be a fun and intriguing experiment. This experiment encourages students to develop their problem-solving skills and attention to detail, as they must carefully analyze and compare the various fingerprint patterns.

Fingerprint analysis is a fascinating and engaging experiment that can spark an interest in forensic science and provide students with a hands-on learning experience.

Learn more: Directions to Examine a Fingerprint

5. Cultivate Bacteria on Home Made Agar

This experiment provides a hands-on learning experience for students to understand the principles of microbiology and the techniques used in bacterial culture.

This experiment can also help students to understand the importance of bacteria in our daily lives, their role in human health, and their applications in various fields, such as biotechnology and environmental science.  

Learn more: Grow bacteria on Homemade Agar Plates

6. Make a Bioluminescent Lamp

This experiment provides an excellent opportunity for high school students to learn about bioluminescence and the principles of genetic engineering.

Creating a bioluminescent lamp is a fun and engaging way to explore the intersection of biology, chemistry, and physics, making it a perfect experiment for students interested in science and technology.

Learn more: Make Glowing Water

7. Make Plants Move with Light

This experiment can help students understand the role of light in plant growth and photosynthesis and the importance of light as an environmental factor for plant survival. 

Learn more: Experiments with Phototropism

8. Test the Five-Second Rule

The “5-second rule” experiment is a simple and fun way to investigate the validity of the popular belief that it is safe to eat food that has been dropped on the ground for less than 5 seconds.

The experiment is an engaging and informative way to explore the science behind a common belief and promote critical thinking and scientific inquiry among students.

Learn more: Five Second Rule

9. Examine How Antibiotics Affect Bacteria

This experiment is an excellent opportunity for high school students to develop their laboratory skills, such as aseptic technique and bacterial culture, and understand the principles of antibiotic resistance and its implications for human health.

Examining how antibiotics affect bacteria is a fascinating and educational experiment that promotes scientific inquiry and critical thinking among students.

Learn more: Learn About Bacteria

10. Look for Cell Mitosis in an Onion

This experiment is an excellent opportunity for high school students to develop their microscopy skills and understand the biological basis of growth and development in plants. This experiment is a fun and informative way to explore the world of cells and their role in the growth and development of living organisms.

Learn more: Onion Root Mitosis

11. Test the Effects of Disinfectants

Testing the effects of disinfectants is an important process in determining their efficacy in killing or reducing the number of microorganisms on a surface or object. Disinfectants can be hazardous if not used correctly, and testing their effects can help students understand how to use them safely.

Students can learn about proper handling techniques and how to interpret safety labels and warning signs.

Learn more: Antiseptic and Disinfectants

12. Microwave Seed Gardening

Microwave seed gardening is a quick and efficient method of germinating seeds, microwave seed gardening can be a useful method for starting seeds, but it should be used with care and in conjunction with other germination methods to ensure the best possible results. 

Learn more: Microwave plant

13. Water Bottle Bacteria Swab

This experiment can be a fun and informative way to learn about the importance of keeping water bottles clean and free from harmful bacteria. It can also be used to compare the cleanliness of different types of water bottles, such as metal, plastic, or glass.

Learn more: Swabbing Water Bottles

14. Frog Dissection

Frog dissection can be a valuable tool for teaching anatomy and physiology to high school students, as it provides a comprehensive examination of the internal organs and systems of the frog.

Dissection can be a valuable and engaging experiment for high school students interested in biology and life science.

Learn more: Frog Dissection

15. Witness the Carbon Cycle in Action

By witnessing the carbon cycle in action, learners can gain a better understanding of the interconnectedness of different parts of the Earth’s system and the impact that human activities can have on these processes.

Learn more: Carbon Cycle Lab

16. Investigate the Efficacy of Types of Fertilizer

Investigating the efficacy of different types of fertilizer can be an interesting and informative way to learn about plant growth and nutrition. Investigating the efficacy of different types of fertilizer is a practical and engaging way to learn about plant nutrition and the role of fertilizers in agriculture.

Learn more: Best Fertilizer

17. Explore the Impact of Genetic Modification on Seeds

Exploring the impact of genetic modification on seeds is a fascinating and relevant topic that can spark meaningful discussions and encourage learners to think critically about the role of science and technology in society.

Learn more: Genetically Modified (GM) Crops

18. Yeast Experiment

Another easy to perform experiment for high school students is the yeast. This experiment is simple since all that is required is the removal of four different food samples onto separate plates and a thorough examination of the mold that develops on each sample over time.

Learn more: Grow Yeast Experiment

19. Taste Perception 

The human tongue has specialized taste receptors that respond to five primary tastes: sweet, salty, sour, bitter, and umami (savory). Taste perception plays an important role in determining food preferences and dietary habits, as well as influencing the overall eating experience.

Learn more: Taste perception

20. Pea Plant Genetics

A classic pea plant genetics experiment involves cross breeding pea plants with different traits, such as flower color, seed shape, or pod shape.

This experiment can be conducted in a controlled environment, such as a greenhouse, by manually transferring pollen from one plant to another.

Learn more: Gregor Mendel Pea Experiment

21. Comparing Animal and Plant Cells

Comparing animal and plant cells is an important exercise in biology education. Both animal and plant cells are eukaryotic cells, meaning they contain a nucleus and other membrane-bound organelles.

This exercise can help students understand the structure and function of cells, as well as appreciate the diversity of life on Earth.

Learn more: Comparing Plant Cell and Animal Cell

22.  Testing Bacteria 

Bacteria are easily accessible and can be grown in a laboratory or even at home with simple equipment and materials. This makes it a practical and cost-effective experiment for schools with limited resources.

Learn more: How to grow Bacteria and more

23. The Effect of Light on Growth

Light is a fundamental environmental factor that plays a crucial role in the growth and development of plants. By conducting this experiment, students can gain a deeper understanding of how light affects plant growth and why it is important.

Learn more: The effect of light in Plant Growth

24. Planaria Regeneration

Planaria regeneration allows students to design their own experiments, as they can choose which body parts to remove and study the effects of different variables, such as temperature, pH, or chemical treatments on the regeneration process.

Planaria are easy to obtain and maintain in a laboratory or classroom setting. They are also affordable, making it an ideal experiment for schools with limited resources.

Learn more: Planaria Experiment

25. Making a Seed Board

Making a seed board can be a fun and engaging activity for students, as they can see the progress of their plants over time and share their results with others. It can also foster a sense of responsibility and ownership in caring for their plants.

26. Design an Owl Pellet

Dissecting an owl pellet provides a hands-on learning experience for students, allowing them to practice skills in scientific observation, data collection, and analysis. Students can also learn about the anatomy of the prey species found in the owl pellet.

27. Grow an Herbal Cutting

Growing an herb cutting provides a hands-on learning experience for students, allowing them to practice skills in plant care, experimental design, and data collection. Students can learn about the different stages of plant growth and the factors that affect it.

28. Eat a Cell Model

Creating an edible cell model connects to various disciplines, such as biology, anatomy, and nutrition. Students can learn about the different organelles that make up a cell and their functions, as well as the nutritional value of the food materials used in the model

29. Make a Habitat Diorama

Making a habitat diorama provides a hands-on learning experience for students, allowing them to practice skills in research, creative design, and presentation. Students can learn about different ecosystems and the organisms that inhabit them.

30. Create a Fall Leaf (or Signs of Spring) Journal

Creating a fall leaf (or signs of spring) journal provides a hands-on learning experience for students, allowing them to practice skills in observation, data collection, and analysis. Students can learn about the changes that occur in nature during the fall or spring season.

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7 Fun Biology Experiments for High School

What better way to learn about life’s mysteries than through exciting and fun biology experiments? High school is the perfect time to delve deeper into the world of biology, and I’ve gathered seven fun and educational experiments that will ignite your students’ curiosity and make biology come alive. So, roll up your sleeves, put on your lab coat, and let’s dive into these fun biology experiments!

1. Barf Bag Lab

Topics: cellular respiration, alcoholic fermentation, cellular energy

Photosynthesis and cellular respiration are difficult concepts for students to grasp because they involve molecular interactions that can’t be seen. Bringing these reactions into an observable format is essential for students to comprehend them. Barf bags do just that.

Not only does the name “Barf Bag Lab” catch their attention, but the reaction itself is just gross enough to be quite memorable. Using yeast to demonstrate alcoholic fermentation, students crush sugary cereal to provide a source of glucose. As the bag expands, it may ultimately “barf” its contents onto the lab table. This lab is a great use of scientific processes because variables can be manipulated by changing the type of cereal used. Grab a free Barf Bag Lab Activity from my online store or see more cellular respiration lab experiments in this post .

2. Osmosis Egg Experiment

Topics: semipermeable cell membranes, osmosis, hypertonic, hypotonic, homeostasis

This classic lab provides another opportunity for students to observe the effects of cellular processes that would otherwise be difficult to see. Unlike the previous lab, however, this one involves a little bit of teacher prep work.

By soaking eggs in vinegar for a few days, the shells become soft and can be washed away with a little water. What remains is a semipermeable cell membrane that is easily observed. By deshelling a few eggs, the cell’s response to a variety of solute concentrations can be illustrated. If you’re interested in incorporating this classic experiment into your course, this egg osmosis lab has been vetted by hundreds of high school Biology teachers.

3. Cell Size Diffusion Lab

Topics: cell size, diffusion, cell membrane, surface area to volume ratio

This is a lab that I use as the first of lesson plan in my cell cycle unit , but it also makes a great diffusion lab. I prefer to do this experiment as a demonstration because it involves bleach and knives, which can be a safety hazard in a high school Biology classroom.

By cutting cubes of fresh beets into different sizes, students can practice calculating surface area and volume, which is a skill that helps them understand the necessity of a cell membrane for the diffusion of substances. Each beet cube is then soaked in bleach and students can observe the percentage of the cube’s volume that is reached by the bleach. The visual component of this lab is a great way for students to comprehend the need for efficient nutrient absorption and the reason for cell division.

4. Extracting DNA from Strawberries

Topics: cell structure, DNA, nucleus, cell membrane, histones

This is another classic lab, but one that just can’t be skipped! With a few household ingredients, students can extract long strings of DNA from the nuclei of strawberry cells and scoop it up with a toothpick or skewer. If you want, the DNA can even be preserved in alcohol as a biology souvenir!

At the beginning of my teaching career, I used the split pea extraction lab from Learn Genetics . It’s still a solid lab, but I’ve come to prefer using strawberries over other DNA sources for two reasons: 1) Strawberries are triploid, so the amount of DNA extracted from them is greater and 2) They are easy to smush. Split pea extraction requires a blender to break the cell walls. Since blenders aren’t readily available for every student, it necessitates a demonstration rather than a lab. Some teachers have found success with wheat germ as a DNA source, as well. You can watch a video demonstration of strawberry DNA extraction on my YouTube channel.

5. Natural Selection Lab

Topics: natural selection, mutation, genetic variation, fitness, antibiotic resistance

It’s tough to find labs for natural selection and evolution because these processes usually have to be simulated rather than observed. One of the most popular natural selection labs is the bird beak activity . Students use a variety of materials to simulate finch beaks and learn how beak adaptations cause different species to show niche separation.

Another one of my favorite evolution simulations is a natural selection lab using various household items to simulate antibiotics and bacteria. Antibiotic resistance is a great topic to incorporate into an evolution unit because it is highly relevant to students. Using a variety of pasta shapes to simulate different bacterial species, students use tools like toothpicks and clothespins to act as antibiotics “killing” the bacterial cells. Mutant bacterial cells aren’t able to be picked up by the tools, allowing these new species to flourish as antibiotic-resistant strains. Looking for more evolution labs? Check out my plant cladogram freebie in this post.

6. Candy Radiometric Dating Lab

Topics: fossils, carbon dating, radiometric dating, isotopes, half-life

Using candy is a go-to in my high school courses because it keeps students interested! There are other supplies that can be used for this radiometric dating lab activity, but candy is always well-received in my classes.

Students begin with a designated number of candies with letters on one side (like Skittles, M&Ms, etc) and they shake the candies in a box or bag to simulate radioactive decay. Candies that have flipped represent the daughter atoms. By repeating the shaking and counting of flipped candies, students can create a graph showing the radioactive decay of an isotope. This easily leads to a discussion of half-lives and the radiometric dating of fossils.

7. Greenhouse Effect Experiment

Topics: greenhouse gases, climate change, fossil fuels, carbon dioxide emissions

The greenhouse effect is easy enough to illustrate. Here’s a quick greenhouse effect simulation , if students aren’t familiar. They have likely also observed the greenhouse effect in their own car or a local greenhouse. The effects of carbon dioxide emissions on the greenhouse effect, however, is not something students readily observe. That’s why this simple lab is so clever. Students set up two plastic zipper bags with a cup of water and a thermometer in each bag. Antacid tablets are added to one cup, producing carbon dioxide within that bag. Students then monitor the difference in temperature over a 30-minute period to see how carbon dioxide intensifies the greenhouse effect. For full instructions on this lab including background reading, student instructions, data tables, and comprehension questions, grab this Greenhouse Effect Experiment .

These fun biology experiments will help your students grasp fundamental concepts and nurture their scientific curiosity. Pick one you haven’t tried, gather your lab equipment, and get going!

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20 Fun and Interesting Biology Experiments for High School 

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Unlike science in middle school, high school biology is a hands-on endeavor. Experiments are a standard part of biology courses, whether they are part of a controlled laboratory class, science fair, or individual student projects. Explore a few fascinating high school biology experiments; and discover ideas for simple and easy biology experiments to incorporate into your curriculum.

Examples of Biology Experiments for High School

Whether you are looking for a science fair project or need to create a project for a class assignment, there are numerous biology projects for teens.

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Frog Dissection

Dissecting a frog is a quintessential part of high school biology. If possible, try to get both female and male specimens for your class so students can see the eggs and compare the insides to the male frog.

Flower Dissection

High schoolers can get a bit squirmy about frog dissection. Have a flower dissection instead. The teens can find and label the female and male parts of the flower. It can be fun for high schoolers to check out flower intricacies under a microscope.

Diversity Among Plant Samples

Another simple biology experiment involves going into your natural environment, such as a local park, to observe diversity among plant samples. To make the experiment more detailed, students can rub collected samples on filter paper to observe which plants present which colors . Teens can work to find out why certain plants present certain colors.

Phototropism

It can be enlightening to show kids how phototropism affects plants. They can set up an experiment by using different materials to affect light. They can see how affecting the light affects the growth of the plant.

Water From Common Sources

Water is everywhere. Unfortunately, water contains numerous elements too. A great experiment is collecting water samples from various sources and viewing them under a microscope. Students can then compare their results and attempt to postulate why a given water source would present more organisms than another would.

Yeast Experiment

Another experiment involves taking a piece of bread to monitor the molds that grow over a period of two weeks.

Taste Perception

Everyone has their own taste. Literally! Some people like sour things while others like sweet. Find out if everyone perceives taste the same way and has the same threshold for taste by doing an in-class experiment.

Disinfectant Effectiveness

Ever wonder how effective hand sanitizer is at killing bacteria? Test it! Grow bacteria in a Petri dish along with paper soaked in peroxide, white vinegar, rubbing alcohol, etc. Find out how each one of them works to inhibit bacteria growth.

Pea Plant Genetics

Students can recreate Mendel's genetic pea plant experiments . By growing pea plants and comparing their phenotypes, students can determine each parent plant's genotype.

Examining Fingerprints

Fingerprints are pretty amazing features on the human body. Not only can you use them to open your phone, but each one is unique . Put your fingerprint on paper and examine the different aspects of the lines and arches on your fingers. Compare fingerprints among everyone in class.

Comparing Animal and Plant Cells

To better understand animal and plant cells, students can compare cells from their cheeks to cells from an onion. Just stain the cells with iodine or another dye to better see the cell structures under a microscope.

Creating a DNA model is a great way to help students understand the structure and function of DNA in genetics. Students can use candy, string, and toothpicks to develop a fairly realistic model of the double helix structure.

Water Bottle Germs

Many people refill their water bottles in high school. But do they add germs or bacteria to the bottle? Is refilling a disposable water bottle safe? Have students take swabs of the water bottles they use and look for bacteria around the lid or on the bottle.

Testing Hair

Teens use a lot of hair products. But do they truly work? Have teens in your class take a few samples of their hair. See what happens to the hair when common hair products are added.

Water Cycle

Understanding the water cycle isn't hard. But teens can look at it firsthand by creating a water cycle experiment. Just have them fill a baggie with water and tape it to a window. They will watch evaporation, condensation, and precipitation in action.

Closed Ecosystem Bottle

It can be hard for students to imagine something having its own ecosystem. However, you can use a plastic bottle to create a closed ecosystem.

Field Survey Biology Experiment

This experiment is great because it is cheap, easy, and you can do it in a variety of areas around your school or send students home with it. The goal is to observe the surrounding area over time and monitor the samples that you collect.

Materials You'll Need

For this experiment, you need to grab:

• Jar or baggies to collect samples
• Stakes and string or cones help mark an area
• Paper or journals for taking notes
• Slides, slide covers, and a microscope

Observation Instructions

Take note that you will observe your area for several months, so choose an area that is easy to re-mark or where you can leave the markings up, so you return to the same designated area each time.

• Have students choose one spot to observe. The spot should be no more than two to three feet square.
• Do you see evidence of animals? (Look for prints, scat or guano, fur, owl pellets, etc.)
• What plant life do you see? (Look for moss, lichen, weeds, and other plants).
• What fungus do you see? (Look for mushrooms and other fungal growth).
• What insects do you see? (Encourage students to look specifically for relationships here - such as connecting mosquitos with water or bees with flowers or a hive).

Sampling and Classroom Instructions

Bring the research back into the classroom by following these instructions.

• Guide students to make connections and note relationships in their marked area. Have them inventory the area and draw a crude map of where everything is.
• If possible, have students use tweezers and gently take samples of soil, fungus, moss, plant life, insects, etc.
• pH value of soil or water
• Microorganisms in water
• Plant cells under a microscope
• Comparative structure of flowers you find
• Require students to record everything in their own journal or interactive notebook.

Teacher tip: Set up stations in the classroom for viewing, dissecting, drawing, testing pH, etc. This will allow students some choice in how they proceed with examining their specimens.

Testing for Bacteria

Have students see where the most bacteria are lurking. This experiment is great if you want a lab that has guaranteed results. There is always some kind of bacteria lurking somewhere, just waiting to grow in a student's Petri dish.

These are the materials you are going to need to have on hand.

• Prepared Petri dishes, three per student
• Sterile swabs
• Painter's tape
• Scotch tape
• Permanent Marker
• Graph paper

Material notes : You can also purchase sterile Petri dishes and agar separately; however, it is much more likely students will contaminate the plate before they swab.

Preparing Your Petri Dishes

Prepping your Petri dishes is an essential part of the experiment.

• Before opening any materials, have students identify three places (but in one physical location such as at home or at school) that they are going to swab for bacteria. Encourage them to hypothesize about which place they think will grow the most bacteria.
• Using the Petri dish, trace three circles on the graph paper and cut it out.
• In pencil, draw a line to denote the 'top' of the circle. It doesn't matter where you draw the line, but you will need something to show you how your Petri dish is oriented so you can be sure you're tracking the same colony each time you observe.
• On the back of the graph paper circle, note the location where you will take the swab, as well as the date you are taking the swabs. Do this for all three Petri dishes you have.

Collecting Samples

Have students bring their unopened sterile swabs and closed Petri dishes to the site. Carefully, they should:

• Set the Petri dish down on a flat surface.
• Unwrap the swab.
• Swipe the swab across the area they suspect has bacteria.
• Lift the lid, gently wipe the used swab across the agar, and close the lid, carefully but quickly.

Hint: Sometimes, it's helpful to tape the Petri dish shut so that the Petri dish doesn't accidentally lose its lid.

Evaluating Results

Now that you've swabbed the areas, it's all about the results.

• Have students draw Petri-dish-sized circles in their lab books or on separate graph paper. Draw one week's worth of Petri dishes for each dish the student has.
• As the colonies start to grow, have students draw the size in their notebooks, making daily observations. If they cannot observe daily, have them observe on the same day(s) over a month.
• They should also be recording the color and other notable features of their bacteria colonies in their lab books.
• At the end, the students should write a conclusion of their study.

The Effect of Light on Growth

In this lab, students investigate how light affects plant growth. Students may use any plants, but cress will grow more quickly, so your students can get results faster.

Gather up your materials.

• Styrofoam cup or bowl
• Potting soil

Instructions

With your materials at the ready, it's time to start your experiment.

• On Day 1 - plant seeds in the soil in the cups.
• Label the cups according to the light you're going to use. You can compare sunlight vs. complete darkness, or you can compare several types of light.
• On each day after the initial day, take a picture of each cup and try to measure the growth, if any.
• For your lab entries, measure the sprouts, and note color and shape characteristics.

Planaria Regeneration

In this lab, students watch the rate at which planaria regenerates and test whether how you cut the planaria makes a difference as to how they grow back.

To conduct this experiment, you want to grab.

• 9 planarias
• 3 small plastic Petri dishes
• 1 large plastic Petri dish
• 1 plastic pipet
• 1 magnifying glass
• 1 plastic coverslip
• Spring water
• Paper towels
• Ice pack(optional)

Setup Instructions

Getting the setup right is half the battle when it comes to creating fun and interesting biology experiments for high schoolers.

• Start by numbering the three small Petri dishes to ensure nothing gets confused later.
• Using the pipet, move a planarian into the large Petri dish.
• At this point, you may want to try to set the Petri dish on an ice pack for a few minutes. This isn't totally necessary, but it will slow the planarian down to make it easier to cut.
• Right behind the head
• Right in the middle
• Right towards the tail
• Use the pipet to gently transfer each segment to a new Petri dish (with spring water).
• Repeat the steps with all remaining worm segments.
• Every day, observe the planaria. Regeneration will be considered 'complete' when the photoreceptors (the black dots that look like eyes on the planarian's head) appear.

Scientific Method and High School Biology Experiments

Much of high school biology is focused on instilling the elements of science in students. The scientific method is one of these main focuses. The method prompts participants in science to be investigators and to come up with a guess about what will happen in a given experiment, called a hypothesis. The point of the experiment is then to either prove the hypothesis correct through the experiment or prove it incorrect. This prompts teens to get involved in the scientific method while teaching other scientific skills, such as:

• The ability to make a rational estimate based on present factors and knowledge
• Close detail and monitoring skills
• The possibility of being wrong and how to move past that if it turns out to be the case
• Quick thinking skills

As much fun as biology experiments can be, there is an educational component spearheading the experiment.

Fun and Interesting High School Biology Experiments

For teens, high school biology can be fun. Finding the right experiment can help biology pop off the page and become more than just another required course of study. Who knows? Perhaps your student will even be prompted to enter a science fair or a career rooted in science?

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70 Best High School Science Fair Projects in Every Subject

Fire up the Bunsen burners!

The cool thing about high school science fair projects is that kids are old enough to tackle some pretty amazing concepts. Some science experiments for high school are just advanced versions of simpler projects they did when they were younger, with detailed calculations or fewer instructions. Other projects involve fire, chemicals, or other materials they couldn’t use before.

Note: Some of these projects were written as classroom labs but can be adapted to become science fair projects too. Just consider variables that you can change up, like materials or other parameters. That changes a classroom activity into a true scientific method experiment!

To make it easier to find the right high school science fair project idea for you, we’ve rated all the projects by difficulty and the materials needed:

Difficulty:

• Easy: Low or no-prep experiments you can do pretty much anytime
• Medium: These take a little more setup or a longer time to complete
• Advanced: Experiments like these take a fairly big commitment of time or effort
• Basic: Simple items you probably already have around the house
• Medium: Items that you might not already have but are easy to get your hands on
• Advanced: These require specialized or more expensive supplies to complete
• Biology and Life Sciences High School Science Fair Projects

Chemistry High School Science Fair Projects

Physics high school science fair projects, engineering high school stem fair projects, biology and life science high school science fair projects.

Explore the living world with these biology science project ideas, learning more about plants, animals, the environment, and much more.

Extract DNA from an onion

Difficulty: Medium / Materials: Medium

You don’t need a lot of supplies to perform this experiment, but it’s impressive nonetheless. Turn this into a science fair project by trying it with other fruits and vegetables too.

Re-create Mendel’s pea plant experiment

Difficulty: Medium / Materials: Medium ADVERTISEMENT

Gregor Mendel’s pea plant experiments were some of the first to explore inherited traits and genetics. Try your own cross-pollination experiments with fast-growing plants like peas or beans.

Make plants move with light

By this age, kids know that many plants move toward sunlight, a process known as phototropism. So high school science fair projects on this topic need to introduce variables into the process, like covering seedling parts with different materials to see the effects.

Test the 5-second rule

We’d all like to know the answer to this one: Is it really safe to eat food you’ve dropped on the floor? Design and conduct an experiment to find out (although we think we might already know the answer).

Find out if color affects taste

Just how interlinked are all our senses? Does the sight of food affect how it tastes? Find out with a fun food science fair project like this one!

See the effects of antibiotics on bacteria

Difficulty: Medium / Materials: Advanced

Bacteria can be divided into two groups: gram-positive and gram-negative. In this experiment, students first determine the two groups, then try the effects of various antibiotics on them. You can get a gram stain kit , bacillus cereus and rhodospirillum rubrum cultures, and antibiotic discs from Home Science Tools.

Learn more: Antibiotics Project at Home Science Tools

Witness the carbon cycle in action

Experiment with the effects of light on the carbon cycle. Make this science fair project even more interesting by adding some small aquatic animals like snails or fish into the mix.

Learn more: Carbon Cycle at Science Lessons That Rock

Look for cell mitosis in an onion

Cell mitosis (division) is actually easy to see in action when you look at onion root tips under a microscope. Students will be amazed to see science theory become science reality right before their eyes. Adapt this lab into a high school science fair project by applying the process to other organisms too.

Test the effects of disinfectants

Grow bacteria in a petri dish along with paper disks soaked in various antiseptics and disinfectants. You’ll be able to see which ones effectively inhibit bacteria growth.

Learn more: Effectiveness of Antiseptics and Disinfectants at Amy Brown Science

Pit hydroponics against soil

Growing vegetables without soil (hydroponics) is a popular trend, allowing people to garden just about anywhere.

More Life Sciences and Biology Science Fair Projects for High School

Use these questions and ideas to design your own experiment:

• Explore ways to prevent soil erosion.
• What are the most accurate methods of predicting various weather patterns?
• Try out various fertilization methods to find the best and safest way to increase crop yield.
• What’s the best way to prevent mold growth on food for long-term storage?
• Does exposure to smoke or other air pollutants affect plant growth?
• Compare the chemical and/or bacterial content of various water sources (bottled, tap, spring, well water, etc.).
• Explore ways to clean up after an oil spill on land or water.
• Conduct a wildlife field survey in a given area and compare it to results from previous surveys.
• Find a new use for plastic bottles or bags to keep them out of landfills.
• Devise a way to desalinate seawater and make it safe to drink.

Bunsen burners, beakers and test tubes, and the possibility of (controlled) explosions? No wonder chemistry is such a popular topic for high school science fair projects!

Break apart covalent bonds

Break the covalent bond of H 2 O into H and O with this simple experiment. You only need simple supplies for this one. Turn it into a science fair project by changing up the variables—does the temperature of the water matter? What happens if you try this with other liquids?

Learn more: Covalent Bonds at Teaching Without Chairs

Measure the calories in various foods

Are the calorie counts on your favorite snacks accurate? Build your own calorimeter and find out! This kit from Home Science Tools has all the supplies you’ll need.

Detect latent fingerprints

Forensic science is engrossing and can lead to important career opportunities too. Explore the chemistry needed to detect latent (invisible) fingerprints, just like they do for crime scenes!

Learn more: Fingerprints Project at Hub Pages

Use Alka-Seltzer to explore reaction rate

Difficulty: Easy / Materials: Easy

Tweak this basic concept to create a variety of high school chemistry science fair projects. Change the temperature, surface area, pressure, and more to see how reaction rates change.

Determine whether sports drinks provide more electrolytes than OJ

Are those pricey sports drinks really worth it? Try this experiment to find out. You’ll need some special equipment for this one; buy a complete kit at Home Science Tools .

Turn flames into a rainbow

You’ll need to get your hands on a few different chemicals for this experiment, but the wow factor will make it worth the effort! Make it a science project by seeing if different materials, air temperature, or other factors change the results.

Discover the size of a mole

The mole is a key concept in chemistry, so it’s important to ensure students really understand it. This experiment uses simple materials like salt and chalk to make an abstract concept more concrete. Make it a project by applying the same procedure to a variety of substances, or determining whether outside variables have an effect on the results.

Learn more: How Big Is a Mole? at Amy Brown Science

Cook up candy to learn mole and molecule calculations

This edible experiment lets students make their own peppermint hard candy while they calculate mass, moles, molecules, and formula weights. Tweak the formulas to create different types of candy and make this into a sweet science fair project!

Learn more: Candy Chemistry at Dunigan Science on TpT

Make soap to understand saponification

Take a closer look at an everyday item: soap! Use oils and other ingredients to make your own soap, learning about esters and saponification. Tinker with the formula to find one that fits a particular set of parameters.

Learn more: Saponification at Chemistry Solutions on TpT

Uncover the secrets of evaporation

Explore the factors that affect evaporation, then come up with ways to slow them down or speed them up for a simple science fair project.

Learn more: Evaporation at Science Projects

More Chemistry Science Fair Projects for High School

These questions and ideas can spark ideas for a unique experiment:

• Compare the properties of sugar and artificial sweeteners.
• Explore the impact of temperature, concentration, and seeding on crystal growth.
• Test various antacids on the market to find the most effective product.
• What is the optimum temperature for yeast production when baking bread from scratch?
• Compare the vitamin C content of various fruits and vegetables.
• How does temperature affect enzyme-catalyzed reactions?
• Investigate the effects of pH on an acid-base chemical reaction.
• Devise a new natural way to test pH levels (such as cabbage leaves).
• What’s the best way to slow down metal oxidation (the form of rust)?
• How do changes in ingredients and method affect the results of a baking recipe?

When you think of physics science projects for high school, the first thing that comes to mind is probably the classic build-a-bridge. But there are plenty of other ways for teens to get hands-on with physics concepts. Here are some to try.

Remove the air in a DIY vacuum chamber

You can use a vacuum chamber to do lots of cool high school science fair projects, but a ready-made one can be expensive. Try this project to make your own with basic supplies.

Learn more: Vacuum Chamber at Instructables

Put together a mini Tesla coil

Looking for a simple but showy high school science fair project? Build your own mini Tesla coil and wow the crowd!

Boil water in a paper cup

Logic tells us we shouldn’t set a paper cup over a heat source, right? Yet it’s actually possible to boil water in a paper cup without burning the cup up! Learn about heat transfer and thermal conductivity with this experiment. Go deeper by trying other liquids like honey to see what happens.

Build a better light bulb

Emulate Edison and build your own simple light bulb. You can turn this into a science fair project by experimenting with different types of materials for filaments.

Measure the speed of light—with your microwave

Grab an egg and head to your microwave for this surprisingly simple experiment. By measuring the distance between cooked portions of egg whites, you’ll be able to calculate the wavelength of the microwaves in your oven and, in turn, the speed of light.

Generate a Lichtenberg figure

See electricity in action when you generate and capture a Lichtenberg figure with polyethylene sheets, wood, or even acrylic and toner. Change the electrical intensity and materials to see what types of patterns you can create.

Learn more: Lichtenberg Figure at Science Notes

Explore the power of friction with sticky note pads

Difficulty: Medium / Materials: Basic

Ever try to pull a piece of paper out of the middle of a big stack? It’s harder than you think it would be! That’s due to the power of friction. In this experiment, students interleave the sheets of two sticky note pads, then measure how much weight it takes to pull them apart. The results are astonishing!

Build a cloud chamber to prove background radiation

Ready to dip your toe into particle physics? Learn about background radiation and build a cloud chamber to prove the existence of muons.

Measure the effect of temperature on resistance

This is a popular and classic science fair experiment in physics. You’ll need a few specialized supplies, but they’re pretty easy to find.

Learn more: Temperature and Resistance at Science Project

Launch the best bottle rocket

A basic bottle rocket is pretty easy to build, but it opens the door to lots of different science fair projects. Design a powerful launcher, alter the rocket so it flies higher or farther, or use only recycled materials for your flyer.

More Physics Science Fair Projects for High School

Design your own experiment in response to these questions and prompts.

• Determine the most efficient solar panel design and placement.
• What’s the best way to eliminate friction between two objects?
• Explore the best methods of insulating an object against heat loss.
• What effect does temperature have on batteries when stored for long periods of time?
• Test the effects of magnets or electromagnetic fields on plants or other living organisms.
• Determine the best angle and speed of a bat swing in baseball.
• What’s the best way to soundproof an area or reduce noise produced by an item?
• Explore methods for reducing air resistance in automotive design.
• Use the concepts of torque and rotation to perfect a golf swing.
• Compare the strength and durability of various building materials.

Many schools are changing up their science fairs to STEM fairs, to encourage students with an interest in engineering to participate. Many great engineering science fair projects start with a STEM challenge, like those shown here. Use these ideas to spark a full-blown project to build something new and amazing!

Construct a model maglev train

Maglev trains may just be the future of mass transportation. Build a model at home, and explore ways to implement the technology on a wider basis.

Learn more: Maglev Model Train at Supermagnete

Design a more efficient wind turbine

Wind energy is renewable, making it a good solution for the fossil fuel problem. For a smart science fair project, experiment to find the most efficient wind turbine design for a given situation.

Re-create Da Vinci’s flying machine

Da Vinci sketched several models of “flying machines” and hoped to soar through the sky. Do some research into his models and try to reconstruct one of your own.

Learn more: Da Vinci Flying Machine at Student Savvy

Design a heart-rate monitor

Smartwatches are ubiquitous these days, so pretty much anyone can wear a heart-rate monitor on their wrist. But do they work any better than one you can build yourself? Get the specialized items you need like the Arduino LilyPad Board on Amazon.

Race 3D printed cars

3D printers are a marvel of the modern era, and budding engineers should definitely learn to use them. Use Tinkercad or a similar program to design and print race cars that can support a defined weight, then see which can roll the fastest! (No 3D printer in your STEM lab? Check the local library. Many of them have 3D printers available for patrons to use.)

Learn more: 3D Printed Cars at Instructables

Grow veggies in a hydroponic garden

Hydroponics is the gardening wave of the future, making it easy to grow plants anywhere with minimal soil required. For a science fair STEM engineering challenge, design and construct your own hydroponic garden capable of growing vegetables to feed a family. This model is just one possible option.

Learn more: Hydroponics at Instructables

Grab items with a mechanical claw

Delve into robotics with this engineering project. This kit includes all the materials you need, with complete video instructions. Once you’ve built the basic structure, tinker around with the design to improve its strength, accuracy, or other traits.

Learn more: Hydraulic Claw at KiwiCo

Construct a crystal radio

Return to the good old days and build a radio from scratch. This makes a cool science fair project if you experiment with different types of materials for the antenna. It takes some specialized equipment, but fortunately, Home Science Tools has an all-in-one kit for this project.

Learn more: Crystal Radio at Scitoys.com

Build a burglar alarm

The challenge? Set up a system to alert you when someone has broken into your house or classroom. This can take any form students can dream up, and you can customize this STEM high school science experiment for multiple skill levels. Keep it simple with an alarm that makes a sound that can be heard from a specified distance. Or kick it up a notch and require the alarm system to send a notification to a cell phone, like the project at the link.

Learn more: Intruder Alarm at Instructables

Walk across a plastic bottle bridge

Balsa wood bridges are OK, but this plastic bottle bridge is really impressive! In fact, students can build all sorts of structures using the concept detailed at the link. It’s the ultimate upcycled STEM challenge!

Learn more: TrussFab Structures at Instructables

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For some further advice go to Use of Animals note at the end.

TWO MAIN APPROACHES FOR A STUDENT EXPERIMENT

In general there are two main methods used in senior high school student experiments. They are:

The method of artificial variation: where you manipulate one variable to see the effect on the other (and keeping the rest constant) For example, what is the effect of temperature (the manipulated or independent variable, IV) on the enzyme digestion of starch (the dependent variable, DV).

The method of concomitant variation: where some naturally occurring variation in some condition (Variable 1) is correlated against some other condition (Variable 2). This is also called a "correlation method". You can think that nature has manipulated the variables but it is still appropriate to class one as dependent and one as independent. For example, do young leaves have the same density and distribution of stomata as older leaves; or how does temperature (IV) in a natural environment affect stoma opening (DV)? In this second case you do not need you to control the environmental temperature, but you do need to measure the DV at different temperatures.

The difficulty with the second approach is the control of other potentially influential variables (such as humidity - as you have to take what you get). However, that does not preclude the variables in relationship being considered the IV and DV or being graphed as such. One way to address the confounding variables (eg humidity) is to collect data on the other variable as well. That is, call the stoma/temperature data Part I, and call the stoma/humidity data Part 2. You can run the statistics on each pair separately, but, for students who are not that "stats-savvy" then they could look for interactions between them at a visual level. [My thanks to Marilyn Love, Science Department, All Hallows' School, Brisbane for this example].

FOOD TECHNOLOGY OPTIONS

Does the amount of bacterial growth in food differ according to its preparation or handling? Although some micro-organisms are deliberately used to make foods such as yoghurt and cheese, other microbes 'spoil' food. Food, as well as meeting the nutritional requirements of humans, will also meet the nutritional needs of a vast range of micro-organisms. These microbes will multiply rapidly in food, given the appropriate conditions such as temperature, pH and moisture.

The flavour, aroma and texture will ultimately be affected. Microbial contamination accounted for 34% of all food recalls by Food Standards Australia New Zealand (FSANZ) between 1 January 1990 and 31 December 2004. Of these recalls, 41% were due to Listeria monocytogenes contamination; 19% were due to Salmonella contamination and 13% were from Escherichia coli contamination (Food Standards 2010). Those most affected by food poisoning are the elderly, the young and immune suppressed individuals. This student experiment is suggested by Biology teacher Sylvia Hicks from St Aidan's College, Corinda.

Effects of different anti microbials on bacterial growth

Joseph Lister first introduced aseptic surgery in 1867 when he used a spray of carbolic acid (phenol C 6 H 5 OH) as a germicide. He was able to reduce mortality of post operative surgery by up to 45%. Since then the control of growth by antimicrobial compounds has grown into a multi-billion dollar industry. A good student experiment is to assess the effect of a variety of antimicrobial disinfectants on bacterial growth.

Charmaine Keal (HOD - Science at Tullawong State High School) offered this advice: "the most popular is testing the effects of different anti-microbials on bacterial growth. Our labbies prepare the plates and order in E.coli . Students then put a 'wash' of E.coli on the agar. Small paper discs (like out of a hole punch) are sterilised and then soaked into different anti-microbials. The discs are placed onto the agar plates and then into the incubator for a couple of days. If the anti bacterial is effective there is a clear ring around the disc where the E.coli have not grown. Students have used the width of this ring to indicate effectiveness (and to collect quantitative data). The experiment can work quite well; keen students have then researched the active compounds within the antibiotic, how they act upon the bacteria and link to the results observed".

Common antibacterials are alcohols (eg ethanol, isopropyl alcohol), synthetic detergents = QAC (quaternary ammonium compounds) or phenols. No single disinfectant is ideal. Each has its advantages and disadvantages. For example, phenols sterilise well but are corrosive and toxic. Detergents and 70% alcohol have some microbiocidal effect but are not sporicidal and dry out skin surfaces. At Mt Maria College, Enoggera, Brisbane, the Science Co-ordinator Shan Wainwright also uses multi disks impregnated with antibiotics. Risk assessment including disposal of waste is vital.

The images in the diagram to the right were prepared by Dr Dennis Kunkel of Dennis Kunkel Microscopy Inc. using light and electron microscopy. Over years Dennis has assembled a vast collection of these micrographs, many of which have been colorized and can be viewed on his website. Images Copyright Dennis Kunkel Microscopy, Inc. used with permission.

Some photos below taken from the student experiment of a Yr 12 Biology student at Our Lady's College, Annerley, Brisbane.

Do probiotics survive the digestive tract as claimed?

The following suggestion is courtesy of Adam Delroy, Moreton Bay College, Brisbane.

Probiotics are live bacteria and yeasts that are good for your health, especially your digestive system. We usually think of bacteria as something that causes diseases. But your body is full of bacteria, both good and bad. Probiotics are often called "good" or "helpful" bacteria because they help keep your gut healthy.

Probiotics are naturally found in your body. You can also find them in some foods and supplements (eg Yakult, Inner Health Plus, Greek yoghurt). Supposedly they can lower the amount of "bad" bacteria in your digestive system that can cause infections or other problems. However, are probiotics able to survive the pH variations of exposure through the intestinal tract to offer health benefits?

In the task we use for the Year 10 Technology & Applied Science extension classes at Moreton Bay College, students were able to select a probiotic (either Lactobacillus acidophilus probiotics or Bifidobacteriam probiotics) and test whether these microbes are able to survive the pH exposures found in the mouth, oesophagus, stomach, proximal and distal small intestine and large intestine to offer their health benefits.

The task sheet, prepared by teacher Adam Delroy, can be downloaded here . After trying a general purpose nutrient agar medium, growth was very poor so a lactobaccilus-specific medium was tried (MRS Agar from Thermo Scientific). This worked well. Details are available here . The MBC microbiology laboratory protocols can be downloaded here .

Killing black mold with clove oil

After the Brisbane floods of January 2011 thousands of homes were affected by mold (or "mould") growing on walls, ceiling and carpets. Flood waters are known to contain viruses, molds and bacteria that can easily become air borne, and combined with sewage and toxins in flood waters this makes a dangerous combination. Even after flood waters recede, the residue left behind contains the same micro-organisms. Insurance companies wouldn't bother to clean moldy carpets because many molds produce mycotoxin which is very dangerous for humans as well as animals. Tightness of the chest, cough, nose bleeds, fever, headache, flu, etc. are some of the most common health hazards of this mold. In fact, the Queensland floods saw seven people hospitalised with the deadly bacterial infection Leptospirosis, due to the micro-organism Leptospira borgpetersenii ( serovar Arborea ); and it was the first time it had been seen in central Queensland. Click the link for the abstract of an article about it published in Epidemiology and Infection (V141, No. 3, Marr 2013, 585-590) by J. K. G. Smith, M. M. Young, K. L. Wilson and S. B. Craig - scientists from the Queensland Department of Health.

One common way to get rid of mold is to wash the affected area in a clove oil solution. This suggests a good student experiment with great practical significance. You could grow some mold on bread (such as the black-green mold pictured below) and place a few drops of a solution of it on a nutrient agar plate and then incubate it. Measure the size of the colony after a few days and then place a square of filter paper on the agar with various amounts of clove oil added and note the growth over the next week. As another treatment you could add the clove oil filter paper at the time of innoculation. How much clove oil to use? Try trial and error but Shannon Lush, in her book "Spotless", suggests a solution of half a teaspoon of oil (2.5 mL) of clove oil (from a pharmacy, supermarket or health food store) to 1 litre of water will kill the spores 24 to 48 hours. Be warned: you will need to consider health risks before you get started, and your teacher will need to approve your plans.

Year 12 student Mitchell Oxley from Redlands College, Brisbane, found this was too weak and stepped it up by a factor of 10. Another favourite is cinnamon oil; you could try that too. If you want to control the type of mold present - and consider the naturally occuring molds too haphazard - then you could consider buying a specific strain. Southern Biological from Brisbane supplies Penicillium chrysogenum as a safe alternative for use in schools. It costs about $15 and comes in a malt extract agar.

Factors affecting enzyme function

Tullawong SHS has their Year 11 Biology students perform the experiment titled "Break it down" ( Biology One Activity Manual , p124 - 128) as an introduction to an enzyme digestion of starch student experiment. Once the experiment is completed, students are required to design and conduct a modification to this experiment for their student experiment whereby they investigate one of the variables that affects the rate of digestion in animals. Click this link to download their Yr 11 Starch student experiment task sheet .

This approach is fairly common in Year 11 as it allows students to concentrate on particular aspects of the student experiment and to develop investigative techniques prior to an "open inquiry" approach in Year 12. Click this link to download their Yr 12 Open Inquiry student experiment task sheet . Note: the school limits task sheets to two pages thus other support material is handed out separately. For example: Click this link to see their Year 12 student experiment Report Guidelines . My thanks to Tullawong SHS Biology teachers: Charmaine Keal (HOD Science), Miriam Kissane, Carey Kearney and Shannon Trims.

Enzyme functioning

All Hallows' School, Brisbane, runs an open inquiry student experiment in Year 12 around the topic of enzymes. During the study of 'Functioning Organisms', students conduct an student experiment to engage with an aspect of plant or animal physiology that allows optimal homeostatic levels to be maintained.

Whilst students may choose various aspects of physiology, such as rates of photosynthesis or respiration, membrane permeability or diffusion rates, a popular experiment involves enzyme activity. The students select an enzyme to investigate, which they research in order to learn how that enzyme contributes to homeostasis, particularly within humans. An example here may involve the use of Bromelain found in pineapples to assist in the digestion of proteins. Students then conduct a number of trials involving their enzyme and a key substrate which they can link to physiology.

The time-consuming nature of the practical work and the difficulty in obtaining quantitative results are often offset by the quality of scientific techniques required, the scope for constant improvement of the method and the creativity required to transform qualitative results into a quantitative scale in order to make meaning of the results. Biology teacher Linda Anderson has supplied the task in OneNote format and can be downloaded here and edited. It is also available in pdf format . Please note that some references apply to the All Hallows' intranet and will not be available. A suggested list of enzymes and procedures for making them up is also available from Linda for download. Photos from her students' student experiments follow:

The final experiment shown in the photos above (far right) involved examining the effect of lipase on the emulsification of fat through testing the rate of emulsification of the different rates of digestion when varying the fat content of the milk. Alternatively, some students examined the effect of the emulsification of fat through the use of different quantities of dishwashing liquid to mimic the act of bile salts to see what effect this has on the speed of the reaction.

Digestion of milk

Are there health implications of consuming large quantities of full cream milk? Should low fat milk be accessible in school tuckshops? Should flavoured milks be made with low fat milk? Does the addition of certain minerals affect the digestion rate of milk, such as PhysiCAL?

Lactic acid and the fermentation of milk Lactic acid forms in milk due to the action of fungi and bacteria acting on the lactose sugar. The most important lactic acid producing bacteria is Lactobacillus. The presence of lactic acid, produced during the lactic acid fermentation is responsible for the sour taste and for the improved microbiological stability and safety of the food. A good student experiment might be to investigate the factors influencing the rate of formation of lactic acid upon the addition of some starter bacteria (eg plain yoghurt). I won't say what they are but a couple of the following are suspects: heat, amount of bacteria added, light, access to air, shape of container, sugar concentration, initial pH, amount of fat (normal, low fat, skim), degree of agitation, and so on.

The acidity of milk is sometimes measured by titration with a 0.1 M NaOH solution, and indicates the consumption of NaOH up to a phenolphthalein end point. People sometimes wrongly assume that the "titratable" acidity is due to lactic acid - an organic acid with the formula CH 3 -CHOH-COOH. However, fresh milk contains practically no lactic acid and the consumption of NaOH is used to change the pH-value of the following components: carbon dioxide, citrates, casein, albumin and phosphates which gives the appearance of a lactic acid concentration of about 0.13% The determination of "acidity" in fresh milk by means of titration is therefore more a measure of the buffer action of milk than anything else. You would call this the "initial" acidity.

In an student experiment, it is likely that you want to talk about the "developed acidity", which is the result of bacterial activity producing lactic acid during milk collection, transportation, and processing. You measure "titratable acidity" (rather than calling it "lactic acid concentration") but acknowledge the errors and subtract the initial "acidity" from the subsequent values obtained during the experiment. Be careful if you intend to measure titratable acidity as a function of time eg "time elapsed"  (rather than just as a function of some manipulated variable (such as temperature). See the note that follows. As a rough guide, one of my students measured the titratable acidity of milk as 0.0288M as lactic acid (7.10 mL titre) at the start, and on day 7 the value was 0.0815M (15.65 mL titre). The in-between values did not give a linear graph; it had a nice curve.

Note about identifying variables : "time elapsed" can be a controlled variable or independent variable (or both) in this experiment (and others that involve collecting data over a period of time). CASE 1: In the fermentation experiment you may, for example, choose to have the "temperature" as the independent (manipulated) variable (say 0°C,10°C, 20°C, 30°C...) and "titratable acidity" as  the dependent variable.  If these are measured just once, say after 1 week, then "time" is a controlled variable (along with initial pH, sunlight, sugar concentration, aeration, exposed surface area etc). You could prepare a graph where you plot "titratable acidity" (y-axis) and temperature (x-axis) and there will be one line.

CASE 2: However, "time" can be an independent variable as well. You use the "temperature" as the independent variable but if you measure the dependent variable (titratable acidity) every week at 0, 1, 2 and 3 weeks then you really have two experiments in one. There are two independent variables: "time" and "temperature" but they can be examined separately. A plot of titratable acidity (y-axis) vs time (x-axis) would show 4 lines (if you used 4 different temperatures). This would be most valuable as it would show you the fermentation rate at each temperature.

You could prepare another graph where you plot titratable acidity (y-axis) and temperature (x-axis) to get 4 lines (one for each weekly measurement including the titratable acidity at t=0). This would be harder for you to visualise and interpret however. The two graphs together could be analysed "... to identify relationships between patterns, trends..." IP3 (VHA) and "analysis and evaluation of complex scientific interrelationships" (EC1, VHA). The two graphs provide stronger evidence for inter-relationships than either graph alone.

Which ferments best: glucose, fructose or sucrose?

Another terrific idea for a wine student experiment. The two common fruit sugars used in winemaking are glucose and fructose. Grape juice is made up of these in roughly equal quantities. Another sugar used in the fermentation industry is sucrose (cane sugar). Sucrose is frequently used as a cheap carbohydrate by breweries, wineries and other fermentation-based industries employing yeast. It is a di-saccharide composed of D-glucose and D-fructose linked by an alpha-1,4 glycoside bond. In the initial stages of fermentation, sucrose is rapidly hydrolyzed into glucose and fructose by the action of the enzyme invertase on this bond. Then the sugars are transported across the cell membrane where they ferment and form alcohol. So investigating the fermentation of sucrose is really also about studying the fermentation of a mixture of glucose and fructose. This suggests a terrific student experiment: to look at the reaction rates of glucose, fructose and sucrose. I am indebted to Savannah from Coolum State High School for suggesting this to me.

At the start of fermentation, grape juice contains approximately equal amounts of glucose and fructose (called 'hexose' sugars). While both are fermented by wine yeasts to ethanol and carbon dioxide, Saccharomyces cerevisiae consumes glucose faster than fructose because this yeast is know to prefer glucose (and so is called a glucophilic or ‘glucose-loving’ yeast). As fermentation proceeds the ratio of fructose to glucose increases. Therefore, fermented grape juice will contain more fructose than glucose as residual sugar. Fructose is the sweetest hexose sugar, approximately twice as sweet as glucose, and thus the wine gets an undesirable fructose sweetness, unbalanced by the sweetness of glucose.

So here is the starting point if you are doing an student experiment. Pose the Research Question: "How do the fermentation rates of glucose, fructose and sucrose compare?" Potentially it is a fantastic student experiment. Studies have found that glucose and fructose ferment at equal rates when they ferment separately; and when their concentrations are above 1%. However, when the glucose is below 1% it reacts faster than fructose. One delicious complication though is that when glucose and fructose are mixed (as in the case of fermenting sucrose; or in an artificial mixture) the glucose ferments faster than fructose. Glucose seems to inhibit fructose. Hmm – now that is tricky.

Your student experiment could look at the fermentation rates of glucose and fructose separately - keeping everything the same except the independent variable of initial concentration. Note that 1% seems to be some sort of cut-off so examining concentrations either side of this would seem laudable. An then look at a mixture - or just look at sucrose as a natural mixture. What are you going to measure? The progress of the fermentation can be assessed by measuring the concentration of residual sugar or of the ethanol, or by the amount of CO2 produced. Sugar concentration can be measured using a Brix refractometer; or in the case of the two reducing sugars glucose and fructose, you can do a Fehling's titration; and there is a titration for ethanol. The density can also be used as an index. You could also monitor the reaction with a gas pressure sensor. I've used the Vernier sensor with a Texas CBL2 and that works well. There are lots of other gas sensors too.

A good start into the experimental glucose/fructose/sucrose fermentation is Leanie Mocke's 2013 Master of Science (Biochemistry) Thesis from Stellenbosch University, South Africa entitled Kinetic Modelling of Wine Fermentations: Why Does Yeast Prefer Glucose to Fructose? [available on-line].

Ginger Beer - avoiding the headaches

Investigating the production of alcohol in wine can give you a few headaches - particularly if you think someone will drink your experiment. Dr Gary Turner, HoD Xavier Catholic College (Hervey Bay) suggests that for Chemistry student experiments a good alternative is ginger beer using a 7-day fermentation recipe (see later). This may be also suitable if your school doesn't allow you to have alcoholic beverages on campus - even in an experiment.

Ginger beer is made traditionally by the yeast fermentation of a mix of sugar, water and ginger.  It is rarely produced commercially but often home brewed. The beverage produced industrially is generally not brewed (fermented), but carbonated with pressurized carbon dioxide. It is really just a soft drink, sweetened with sugar or artificial sweeteners. However, there are some manufacturers who still brew it the old way: in Queensland, Bundaberg Brewery produces an excellent brewed ginger beer. It is cloudy and if you hold the bottle up to the light and you'll see it's full of ginger pieces. A good student experiment would be to brew your own at home or in the lab using one of the many recipes available on the internet ( but do NOT drink it ; not for an student experiment).

Gary suggests this for his Year 12 student experiment: First: You will be following a 'standard' procedure for making a simple beer (e.g. two-day ginger-beer) to give you the background skills and chemistry involved in making a beer, and to explore the factors involved. This section of the work will also require you to define which factors you can reasonably test in a school-laboratory, and which variables in the production that you can vary. A copy of the student experiment task sheet is available for download here .

"The students can try the variables of yeast, sugar, and temperature (by dividing batches into samples) and titrate for alcohol at intervals (many hands makes light-work). You need a fridge and an incubator to give you three temps (including room temp) for the temp-as-variable". His method is one of many that can be easily obtained from the internet:

Alcohol is produced but its concentration is likely to be under 1%. Also, most fermented soft drinks are acidified to inhibit bacterial growth. Does this also inhibit the yeast? You could investigate the effect of pH on the rate of fermentation using lemon juice or better - citric acid. The juice of 1 lemon contains about 12 g citic acid. Be warned - you should not be drinking the ginger beer unless you have approval from your teacher (and this is unlikely). Drinking stuff made in a laboratory with no hygiene controls is DEFINITELY NOT PERMITTED.

Lastly, what sort of yeast is best? Chemistry teacher Torsten Pluschke of Atherton State High School (North Queensland) said that you could buy genuine ginger beer plant (a SCOBY - symbiotic colony of bacteria and yeast, rather than just baker/brewer's yeast) online. He said that it must be looked after, and consumed in a shorter time frame than baker/brewer or wild yeasts. One online site (no recommendations given though) is The Ginger Beer Plant who can provide a 50 g sachet of the SCOBY for about $20 including postage to Australia. I asked at my local brew shop and the guy said none was available in Australia and it had to be bought online.

However, what yeast do you think Bundaberg Brewed Drinks use for their Brewed Ginger Beer? Here's what Richard Cowdroy-Ling, General Manager Business Technologies, said about their product:

Denaturing albumin 'egg white' with copper

'Egg white' is the common name for the clear liquid contained within an egg. It is also called the albumen or the glair/glaire. When cooked, the albumin turns white and opaque. It is said to have been denatured . Many processes (eg beating) can denature albumin. So too can chemicals. One such chemical is copper sulfate. The copper ions break down the tertiary structure causing the protein to denature. The higher the concentration of the copper sulfate the faster and more opaque the albumen will turn. A practical example of this is the use of copper bowls to stabilize egg foams. The copper in the bowl assists in creating a tighter bond in reactive sulfur items such as egg whites.

A good student experiment would be to see how the concentration of copper sulfate solution affects the degree of denaturing. I would start with copper ion concentrations ranging from 0.002M to 0.01M CuSO 4 . If you don't do chemistry then perhaps you could find out what the "M" concentrations mean, or just do it as grams/litre. A 0.001M solution of copper sulfate pentahydrate (which is what you'll have in the lab) is made up of 0.250 g/L. For chemistry students, note that the molar mass of the pentahydrate is 250g/mol. One way of obtaining quantitative results is to centrifuge the solutions after denaturation has occurred and this will show how much of the albumen has been denatured. The centrifuge tubes are usually graduated.

Nitrification in Soils - a great titration prac. A great student experiment concerns the process of nitrification by soil bacteria. It would be suitable for either Chemistry or Biology. It is also broadly related to wastewater treatment and maintenance of fish aquariums.

Nitrogen is one of the most essential nutrients for plants and is most frequently the limiting factor in crop productivity. The vast majority of the total nitrogen in soil (>98%) is in organic matter, which can't directly be used by plants. It must be converted to inorganic forms as either ammonium (NH 4 + ) or nitrate (NO 3 - ). This conversion occurs via a biological process called nitrification involving soil microorganisms. 

Nitrification in nature is a two-step oxidation process of ammonium ion or ammonia to nitrate ion catalyzed by two types of bacteria. The first reaction is oxidation of ammonium to nitrite by ammonium oxidizing bacteria (AOB) represented by the Nitrosomonas species. The second reaction is oxidation of nitrite (NO 2 - ) to nitrate by nitrate-oxidizing bacteria (NOB), represented by the Nitrobacter species.

The progress of nitrification can be investigated using a fairly common titration procedure. It involves making a filtered solution of the soil, boiling off free ammonia, adding an excess of sodium hydroxide solution (which reacts with the ammonium ion) and back-titrating the excess hydroxide with standardized hydrochloric acid. The method can be easily found on the internet and may even be in your textbook under a heading of "analyzing fertilizer". The photos below are courtesy of Yr 12 student Jamie from Our Lady's College, Annerley, Brisbane.

A good mixed source of nitrifying bacteria and ammonium ions is potting mix. It usually contains peat moss, sand, and other organic material such as wood chips. It usually has reasonable amounts of ammonium ions present. Your student experiment could be to measure the ammonium ion concentration after a period of time (say a week) under different conditions that may affect the bacteria (temperature, oxygen availability, pH, salinity, light).

Temperature: nitrifiying bacteria are supposed to be at their optimum from 25°C-30°C. Aquarium operators have a rule of thumb that says: 50% activity at 20°C, 25% at 10°C, 0% at 4°C and are death at 0°C. When heated, their activity decreases after 30°C and they die by 50°C. That suggests a great investigation. Oxygen: the bacteria need oxygen to produce energy to live (respiration). If you cut off their oxygen supply their activity decreases. Farmers know that in waterlogged soils the bacteria are less productive. That suggests waterlogging your potting mix samples to prevent the bacteria getting oxygen and comparing them to the control. It would be good to know how much water is present in the potting mix and you can do this by taking a weighed sample and drying it in the oven at 100°C (gravimetric analysis). Because the hydroxide is in the flask, the end point will be when the pink just disappears. The flasks at the end point. Moisture: nitrifying bacteria are most active in a soil that is moist but not saturated (see above). Is there an optimum amount of moisture? If completely dry they go into hibernation - but what is optimum? pH: there is an optimum for the first stage bacteria ( nitrosomanas ) of 7.8 to 8.0, and for stage two ( nitrobacter) it is a little bit less. This investigation would require careful design. Potting mix is usually pH 5-6.5 so you'll have to add some alkali to increase the pH. This will affect the acid/base titration. You'll need to think about a controlled sample without potting mix but with the added base. As a matter of interest, as the ocean becomes enriched in anthropogenic (human activity) CO 2 the resulting decrease in pH could lead to decreasing rates of nitrification. That's another context for this student experiment. Salinity: the optimum is said to be zero to 0.6%. Light: the nitrifying bacteria are supposed to be sensitive to blue/UV light. But how far into the soil would light penetrate (a good design consideration).

My thanks to Chemistry colleague at Our Lady's College, Annerley, Brisbane, Kayleen Solomon and Yr 12 student Jamie for providing ideas and photos for this student experiment suggestion.

Nitrification in Soils - spectrographic determination

In the above suggestion, a back titration was used to determine the ammonium concentration. If you have access to a spectrophotometer and the reagents required you could determine nitrate ion spectrophophotometrically.

Physically, nitrite is a colorless and odorless ion. However, there are spectrophotometric methods for its determination. One example is to react it with an acidified sulfanilamide and N-(1-naphthyl)ethylenediamine dihydrochloride to form an intensely coloured dye having maximum absorption at 540 nm. There are lots of other methods. Often you can get them in the form of test kits where you compare the colour to a test strip. Before you get started check that you can get the reagents.

Soft Drinks and Tooth Decay

A soft drink ( or 'soda') such as lemonade or Coca-Cola is a drink that does not contain alcohol, as opposed to a hard drink, which does. Australians consume about 300 mL of soft drink per day on average but amongst 14-16 year olds the figures are 1000 mL for males and 500mL for females. Soft drinks are about 10% sugar so a young male typically consumes 27 teaspoons of sugar per day in soft drink; a girl, about half that. Just one can of soft drink has about 10 teaspoons of sugar in it. The resultant obesity (fat) epidemic is attributed in part to soft drinks. Health risks from over consumption include diabetes, kidney stones, obesity, osteoporosis, and tooth destruction.

Tooth decay is partly from the bacteria feeding on the sugar but also from the acids reacting with the tooth enamel. The citric or phosphoric acid in soft drink dissolves the calcium out of the enamel leaving a softened matrix for bacteria to enter the teeth and cause wholesale carious (tooth) destruction. So drinking sugar-free (diet) soft drink is not the answer.

A good student experiment may be to look at the effect of drink acids on teeth. Teeth are a form of hydroxyapatite Ca 5 (PO 4 ) 3 (OH) but you can simulate this in the lab with calcium carbonate (marble chips). The problem is: you need to control the type of acid, whether it is phosphoric acid as found in cola drinks, or citric acid as found in lemonade. A study by Fraunhofer and Rodgers (2004) found that the rate of enamel dissolution of teeth was not dependent on pH but may be affected by titratable acidity. Remember that weak acids (phosphoric, citric) are not fully dissociated in water (so their pH is not that low) but they gradually release more hydrogen ions as they react. The "titratable acidity" will be a measure of this. Citric acid, for instance, is a tribasic acid which releases its H + ions in four steps. It has a reversible reaction with CaCO 3 and the reaction is controlled by diffusion of reaction products away from the 'tooth' surface; thus, consider keeping it stirred.

As a trial, I took a 1 cm 3 cube of marble and placed it in 200 mL of 7.5%w/v citric acid solution (pH 1.8) at 50°C (with stirring) and after 60 minutes it had lost 0.30 g. Why not make up a synthetic soft drink from phosphoric or citric acid. What concentration will you choose? How does the reaction rate or the extent of the reaction vary with concentration? Does temperature have much effect on the rate? Does the product - calcium citrate or calcium phosphate - impede the progress of the reaction; that is, how soluble are the products (one is 4 times as soluble as the other). How do you measure the progress of the reaction (amount of carbonate consumed or change in titratable acidity of the solution)? Oh, the possibilities are endless. And you can drink the left-over Coke and rot your teeth a bit more at the same time. A great student experiment.

SOME OTHERS

These below were provided by John Andrews (HOS Science, Matthew Flinders Anglican College, Buderim). They have been taken from his Year 11 Biology task sheet. This task sheet shows numerous suggestions also listed on this webpage but also shows his approach to scaffolding Year 11 experiments. The pdf file may be downloaded here.

• Effectiveness of biological washing powders in removing protein stains.
• Different types of food-processing in relation to shelf-life.

Schools have a variety of sensors to get quantitative data about plant growth and behaviour. For example, at Clairvaux MacKillop College, Diane Mackenzie said that in Year 11 student experiments they focus on plant physiology and use a collection of sensors that includes oxygen, CO 2 , relative humidity, gas pressure, colorimeters, pH and conductivity and students are encouraged to use these in designing and carrying out experiments mainly related to rates of photosynthesis, respiration, transpiration and germination.

What are the "best" conditions for growth of a plant?

There have been about 7000 generations of humans on this planet so far but in only ten of these has there been enough food for the majority of the population in the western world. In 18th Century Britain 20% of the population was not fit to work because of lack of food; they only had enough energy to stay alive. In the 21st century we now have four times as much energy available for work (8000 kJ against 2000 kJ back then). Much of this change has come about by food scientists and farmers working together to maximize the yield of crops.

Factor Variable Comments Light Quantity Use shadecloth (90% shade, 50% shade, 0% shade ie full sun). For radish typical results are 90% 2.5cm growth in 3 weeks, 50% 5.0 cm; full sun 5.7 cm. Quality Use cellophane filters. Green poorly absorbed, blue good for growth, red good for flowering. Duration For example: 'Long-day' plants such as the summer-flowering plants, as well as many vegetables including radish form flowers only when day lengths exceed 12 hours. Temperature Affects the productivity and growth of a plant via rates of photosynthesis respiration and transpiration; and impacts sugar storage, dormancy and flowering. Increased temperature may make respiration faster than photosynthesis so no growth will occur. Water Humidity The moisture content of the air will impact transpiration and thus growth. Soil water Adequate water and oxygen must be available in the soil. Water is required for nutrient movement into and throughout the roots. Oxygen is required in the soil for respiration to occur to produce energy for growth and the movement of mineral ions into the root cells across their membranes. Salinity Stress High salt represents a water deficit or osmotic stress because of decreased osmotic potential in the soil solution. Also produces ionic stress from too much Na+ and Cl- Nutrition Macronutrient N, P, K, Mg, Ca deficiency leads to poor growth.   Micronutrient Deficiencies: Fe, Mn, Mo gives interveinal chlorosis; Zn "Little leaf" reduction in size of leaves. Problems with excess as well. Others are Co, Ni, B. Foliar absorption Under normal growing conditions plants absorb most nutrients, except carbon, hydrogen, and oxygen, from the soil. However, some nutrients can also be absorbed by the leaves if they are sprayed on with a dilute solution. Atmosphere Carbon dioxide Increasing CO 2 can increase crop yields; decreasing can limit growth.

Basil are better for student experiments done in the warmer months but if you want to do it in winter (as most schools do), then chervil ( Anthriscus cereifolium ) - the french herb - or radish seedlings are great (see photos below).

Moreton Bay College has used radish for the past few years and have found them to be the best for student experiments. They used to get their chervil seeds from Beautanicals at Helidon, a few hours west of Brisbane, phone 07 4697 6306 or email [email protected] . They are great to deal with and 30 fresh seeds cost $3.50. Click here to download Moreton Bay College's Yr 11 student experiment . The Biology teachers from Nanango State High School have also provided their Year 11 student experiment on plant growth: Click here to download Nanango SHS's Yr 11 Plant Growth student experiment .

Your problem will be to ensure the same intensity of light gets through to the plants (yellow may not absorb as much as blue for instance). The image below shows the wavelengths of light most transmitted (passed) by each type of cellophane; this is called their "λTmax" (lambda T max), that is, the wavelength most transmitted. I did this on a spectrometer at Moreton Bay College but you could run them again if you can get access to a spectrometer. You would also need to know what % transmission occurs for each colour; I didn't do that.

VARIABLES Note about identifying variables: "time elapsed" can be a controlled variable or independent variable (or both) in this experiment (and others that involve collecting data over a period of time).

CASE 1: In this leaf growth experiment you may, for example, choose to have the "amount of fertilizer" as the independent (manipulated) variable, and "leaf surface area" as a measure of growth for the dependent variable. If these are measured just once, say after 3 weeks, then "time" is a controlled variable (along with water, sunlight, temperature etc). You could prepare a graph where you plot surface area (y-axis) and concentration (x-axis) and there will be one line.

CASE 2: However, "time" can be an independent variable as well. You use the "amount of fertilizer" as the independent variable but if you measure the dependent variable (surface area) every week at 0, 1, 2, 3, and 4 weeks then you really have two experiments in one. There are two independent variables: "time" and "amount of fertilizer" but they can be examined separately. A plot of surface area (y-axis) vs time (x-axis) would show 3 lines (if you used 3 different concentrations of fertilizer). This would be most valuable as it would show you growth rate at each concentration. You could prepare another graph where you plot surface area (y-axis) and concentration (x-axis) to get 5 lines (one for each weekly measurement including the starting height at t=0). This would be harder for you to visualise and interpret however.

The two graphs together could be analysed for inter-relationships "to identify trends and inter-relationships" IB3 (VHA) and "interpreting and critically analysing results with links to theoretical concepts to draw conclusions" (IB4, VHA). The two graphs provide stronger evidence for inter-relationships than either graph alone. I strongly suggest you consult your teacher about getting the best opportunity to demonstrate an "A" grade, particularly in the two criteria mentioned above (IB3, IB4).

The effect of different concentrations of hormones on the growth of tissue cultured plants

This student experiment follows on from the one above. Some Moreton Bay College students looked at the effect of hormone powder and they used impatiens cuttings and a commercially available rooting powder. Although impatiens is a weed, it is great for cuttings.

The effect of leaf vs root application of water to a plant

I must thank Yr 12 student James Hunter from Faith Lutheran College, Plainlands, Queensland (between West Ipswich and Toowoomba) for providing notes about his Biology student experiment. He lives in a prime agricultural area and was concerned about the effect of salinity on crops. He made the point that one-quarter of the arable land in Australia is affected by salinity; predominantly dryland salinity (caused by the removal of deep-rooted trees and shrubs and their replacement with crops that do not use as much water), or irrigation salinity (caused by heavily drawing on the water table, bringing water to the surface that contains high level of sodium chloride and other salts).

Irrespective of the cause of the salinity, salt, he said, is left in the soil, contaminating it for future crops. He investigated the effect of various concentrations of sodium chloride in water on two methods of application: "foliar & root" (sprinkler systems) and "direct root" application (drip irrigation system) on a young Sweet Basil crop. That is, he had two manipulated variables (the continuous variable - salt concentration) and a categorical variable - the method of application (either sprinkler or drip).

Some words from his abstract will give you a flavour of his student experiment:

"This investigation studied the effects of foliar & root versus direct root application with saline water on young Sweet Basil crops. Levels were 0ppt (parts per thousand, or g/L), 1ppt, 2ppt, 10ppt or 20ppt water. All hypotheses were supported; as salinity increased past 0ppt, harvest dropped 0-100%. Also, direct root application tests performed 11-17% better than their respective foliar & root application tests due to the roots more advanced restrictive mechanisms. This report suggests using drip irrigation and a minimised use of sprinkler systems as exposure with saline water on leaves seriously damages crops. Also, water brought up by heavy irrigation can be highly dangerous."

In a typical "factors affecting plant growth" experiment students generally make up pots of seedlings and give them different levels of treatment, and each level replicated twice (duplicate) or three (triplicate) times. For example, a student may want to test the effect of five different levels of salinity (as the treatment) on sweet peas and try each one in triplicate (the replicates). Imagine the concentrations of salt in the water (in mg/L) are 0, 10, 20, 30, 40 and 50. So a total of 15 pots (5 treatments x 3 replications) of plants are required. These could be set out as in the diagram below and the different concentrations of salty water added carefully to each pot.

However, nuisance factors can spoil the experiment. For example, the outer pots could get more breeze or light, or the ones facing north could get more sunlight, and the ones in the centre could get more water when being sprinkled. The way to avoid these nuisance factors is to use a Latin Square (for equal numbers of treatments and replicates) or a Latin Rectangle (when the number of treatments is more or less than the number of replicates).

A Latin Square design is a method of placing treatments in a randomised pattern within a block. Treatments appear once in each row and column. Replicates are also included in this design. Figure 2 below shows one of the many Latin Rectangle arrangements for a 5 x 3 array.

Comment from Dr Mel Perkins, Sophia College, Plainland, Qld):

Such differences (above) have the potential to be so great as to mask any treatment-related responses. A typical way of dealing with this issue is to use a randomised complete block design (where each block represents a level of the prevailing gradient, e.g. low, medium or high light intensity) and statistically analyse the data accordingly so that variation due to the 'block effect' is separated from the 'treatment effect'. Plants don't need to be moved during the trial, saving a lot of work! It all hinges on having at least one replicate of each treatment randomly positioned within each block. It also requires knowledge of statistical analysis at a level which I think may go beyond the scope of high school science.

Simpler idea: If there are enough plants available, it is also a good idea to surround the experimental plants with buffer plants not included in the data analysis to minimise 'edge effects' (i.e., those extremes of light, temperature and desiccation typically encountered by plants on the edge of the trial plot).

Effect of temperature and chemicals on a beetroot membrane

For centuries waterways have been used to dispose of household and industrial wastes. Only in about the last 150 years have concerns been raised about the environmental changes this could cause. In about the last 50 years people have carried out detailed research to find out the effects on living things of adding hot water (from industrial cooling systems) and chemical wastes to waterways. Many of these studies have been from an ecological perspective (looking at the changes in the species that are found in an area) or from a health perspective. (Is it safe to swim in the water or eat fish caught there?) It is not possible to observe membranes directly, so this investigation is an indirect study of the effects of different substances and treatments on living beetroot cells.

If the intensity of the colour is your dependent variable, you could make the temperature, or the concentration of various chemicals (eg alcohol) the manipulated variables. If you have a spectrophotometer the λmax = 535 nm. Click here to see an outline of the method. For a copy of the Browns Plains Year 11 Beetroot student experiment task sheet click here.

• What is the maximum temperature a cell can sustain before lysis occurs? (Beetroot)
• How does alteration of temperature impact on the structures of a cell? (Beetroot with microscopes or onion)

Salt damage on a beetroot membrane: effect on osmosis

This suggestion follows on from the one above - and involves spectrophotometric analysis of beetroot. It looks at the osmosis in cells damaged by high salt concentration. It comes from Biology teacher Belinda Coombe from Ryan Catholic College, Townsville.

The vacuole of beetroot plants contains a red pigment, betacyanin, as well as water. Betacyanin will only be found in the vacuole of healthy cells. However, if this membrane becomes damaged, the red pigment will leak out into the surrounding area and indicate the death of the cell. The intensity of the red colour is proportional to the amount of cellular damage. While some salt is essential for plant growth, too much can kill plants as water moves out of the cell through the process of osmosis. A significant reduction in a plant cell's water content causes osmotic stress which affects membrane integrity.

It can be downloaded here: Biological membrane prac (salt, beetroot).

Effect of surface area on a beetroot membrane osmosis

Here's a further investigation of beetroot. A student from Ryan Catholic College (Townsville) wrote: "In this experiment I aim to find out the relationship between the leakage of red pigment from a beetroot cell and the surface area. To do this successfully I will need to alter the surface area of the beetroot cells accurately and then measure if any and how much dye is let out. I can hopefully then look at my results and then find a relationship between the two factors and be able to explain exactly why any changes took place." Some suggested variables: Variables: temperature, time, pH (but you'd need to justify why these may have an effect; it's no good just doing trial-and-error.

Biology teacher Belinda Coombe has provided some additional notes if you want to develop this further. They can be downloaded here: Effect of Surface Area on Beetroot diffusion .

How Size and Shape affects diffusion of ions in agar jelly - a model for cell kinetics

This suggestion comes from Belinda Coombe (Ryan Catholic College). She sees it as the basis for a good student experiment.

All cells must exchange substances with their environment. This occurs through the cell membrane by the process of diffusion, osmosis or active transport. The larger a cell grows, the more exchanging of substances is required. However, this process can be limited by the surface area (ie amount of membrane) that the cell has, relative to the volume of the cell.

In this activity, blocks of agar jelly will be used to simulate different sizes and shapes of cells (or simple organisms). The jelly is a pink colour due to the presence of a base, sodium hydroxide (NaOH), and phenolphthalein indicator. The indicator is pink in a basic solution, but colourless in a neutral or acidic solution. When the blocks are placed in an acid solution, the acid diffuses into the jelly, causing it to change from pink to colourless. The time taken for a block to completely lose the pink colour is a measure of the rate of diffusion of acid into the jelly. You can download her tasksheet here: Size & Shape Diffusion Rate jelly prac.

Functioning Membranes - diffusion, osmosis, turgidity & plasmolysis investigations

If you are looking for some experiments that might form a basis of a good Year 11 student experiment, then this collection provided by Belinda Coombe of Ryan Catholic College may be useful. Download them here: Functioning Membranes Experiments .

She says: "The attached experiments are just 'starter'. If you take the basic idea and then alter a different variable, include more accurate changes in dilutions etc. Note however in the document - Function Membranes Experiment A - diffusion, we don't do any more due to potassium permangante, Exp 2.11 I have found the potatoes are not very successful, however the grapes work beautifully and you could always modify this experiment to weigh the grapes at the beginning and the end of the experiment. The beetroot one works well as well if you have a colorimeter or spectrophotometer - again students can vary the type or concentration of the solution. (varying the concentration of one solution tends to be better as then they have continuous data)."

Egg Membrane osmosis - everyone's favourite

Here's a terrific student experiment suggested by Kim Murray, Biology Teacher, Tannum Sands State High School. She says "The egg experiment works perfectly, and is one of my all-time favourite experiments - and the students love it! We run it over 3 lessons. The experiment is absolutely brilliant for boosting students’ understanding of these topics. It is fantastic and could make a terrific student experiment."

Under the hard outer shell of a chicken egg is a semipermeable membrane that allows air and moisture to pass through. Because water molecules can move into and out of the egg but larger molecules cannot, the semipermeable egg membrane allows for an exploration of the concepts of diffusion and osmosis. Osmosis is the movement of a solvent, such as water, through a semipermeable membrane into a solution of higher solute concentration that tends to equalize the concentrations of solute on the two sides of the membrane. The process of removing the outer shell while leaving the underlying membrane intact presents an additional opportunity for observations, as an acid-base reaction occurs when you make the "naked" eggs for the osmosis experiment. You can download Kim's student tasksheet here: Egg Osmosis Experiment (student) ; or the notes for the teacher Egg Osmosis Experiment (teacher's notes) .

Belinda Coombe says of the egg experiment: "I have also had students in the past use eggs and dissolve the shell first in vinegar, then carefully rub the shell off, they are left with the raw egg in its inner membrane, of which they then weighed the egg and placed in solutions and then weighed again after a period of time (we did lose lots of eggs in the process, but was a neat idea of using an actual membrane)."

For all of these diffusion/osmosis experiments Belinda warns: "Students need to be aware of if they are looking at diffusion or osmosis - this is dependent on the type of solution they are using. There are also further complicating factors such as if the solution is isotonic/hypertonic/hypotonic as this will change the type of graph they are reporting. Some good biology to explain there in the discussion."

However, another teacher warned: "We used to do osmosis/diffusion in the past but I learnt very quickly that unless you own some pretty powerful optical technology it may become an indirect evidence gathering exercise. Yes, you could with an egg after you dunk it in various salt solutions or distilled water. Also you could do something similar with various vegetable matter but the students won’t be actually observing the membrane in action so here you need to make a judgement call on the value of the exercise for the students. My past students found the exercise quite 'nebulous' and lacking 'tangible' outcomes."

Starch and glucose osmosis through dialysis tubing

Here's another suggestion from Kim Murray, Biology Teacher, Tannum Sands State High School. This suggestion is about osmosis using dialysis tubing. She said: "The dialysis tubing one works very well, and could be adapted using different solutions and concentrations.

Download Kim's notes here: Diffusion & Osmosis Experiment using Dialysis Tubing . This experiment is also included in Belinda Coombe's document (Functioning Membranes Experiments) shown above. Belinda says: "We have used the dialysis tubing and then you can vary the type of solution/concentration that you put either outside the bag or inside the bag. There is a change in mass over time either into or out of the bag. This is the "osmosis in model cell" prac at the end of the Functioning Membrane document) It gives nice quantitative results.

Banana ripening kinetics - a great student experiment

When you pick fruit of a tree or vine it remains alive even though it is separated from its parent. They can't get water or nutrients from the parent so they have to use their own stored chemicals to continue. Bananas are like this. Mature green bananas are full of starch, but when you pick them they begin to ripen: their average starch content just before ripening reaches 25% and drops over a few days of ripening to less than 1%. But little is known about the mechanism involved.

It seems that the hormone ethylene triggers the production of enzymes. For example, the α(1→4) bonds of starch may be hydrolyzed by amylases (and glucosidases) or broken by starch phosphorylases. It has been observed that sucrose starts to accumulate first, before glucose and fructose, and parallel to starch disappearance. See N. Terra et al, 1983. "Starch-Sugar Transformation during banana ripening". Journal of Food Science, V48(4) p1097-1100.

This suggests a great student experiment. The question can be asked "What conditions affect the kinetics of banana ripening?" The obvious one is temperature, but an intriguing one is the presence of ethylene (ethene). This gas is produced as bananas begin to ripen so it would be instructive to compare bananas ripening in a plastic bag where the ethylene is trapped in with the fruit, versus ripening in a breeze where the ethylene is blown away. I've used a little fan out of a computer. That's all you need.

What would you measure as an index of ripening? Some books suggest iodine but that may be too inaccurate for a Biology student experiment. I suggest measuring the concentration of glucose. There are a couple of methods of measuring this but the two main ones would have to be: (a) using glucose test strips either by comparison against colour standards, or by use of a glucometer as used in diabetes monitoring; (b) if you also do Chemistry then a titration could be the way to go - using either using Benedict's solution, or an iodine/thiosulfate titration (download).

Diazotroph bacteria as a cereal crop growth promoter

All legumes used in agriculture can use atmospheric nitrogen after it is 'fixed' inside nodules on their roots by a soil bacterium, Rhizobium. The rhizobia receive growth substances from the legume, and the legume receives nitrogen compounds for its growth from the rhizobia. When high numbers of the appropriate rhizobia are not present in the soil, they must be introduced by adding them to the seed at sowing, by a process called inoculation. But can you inoculate non-legume plants with the bacterium?

The winning entry in the world-wide Google 2014 Science Fair Competition investigated this idea. The three girls who won the prize were Ciara Judge (16), Sophie Healy-Thow (17), and Emer Hickey (16) from Kinsale Community School in Cork, Ireland. The students knew that Rhizobia nodules were only found on certain leguminous plants such as peas and beans. But the girls wondered: why wouldn't these bacteria be beneficial to other species - specifically grains like barley and oats, which are integral to our food supply.

Over 11 months, the students tested more than 10,000 seeds, and recorded more than 120,000 individual measurements. When they were finished, they discovered that by infusing their seeds with rhizobia bacteria, the plants germinated in half the amount of time compared to seeds without rhizobia. Moreover, they measured that the mass of the plants increased by as much as 70 per cent. This would be a great student experiment particularly as it could be done in a shorter time and lots of variables to measure control. For more info see http://www.businessinsider.com/google-science-fair-winners-crop-bacteria-2014-9

Allopathy in the germination of seeds

Allelopathy is a biological phenomenon by which an organism produces one or more biochemicals that influence the growth, survival, and reproduction of other organisms. These biochemicals are known as allelochemicals and can have beneficial (positive allelopathy) or detrimental (negative allelopathy) effects on the target organisms. The possible application of allelopathy in agriculture is the subject of much research. Current research is focused on the effects of weeds on crops, crops on weeds, and crops on crops. This research furthers the possibility of using allelochemicals as growth regulators and natural herbicides, to promote sustainable agriculture.

One student, Melissa , said: "We did and experiment in class to see the effect living plants may have on other plants that may be present nearby. This is known as allelopathy. Secondary metabolites cause these allelopathic effects.The most commonly known plant to exhibit this is the black walnut tree. Where a black walnut tree is present, most other plants cannot grow.Walnut trees produce a compund called Juglone, which stops other plants growing. In this experiment we tested the allelopathic effects of walnuts, oranges and lemons on lettuce seeds ( Lactuca sativa ). The aim of the experiment is to establish if the listed plants inhibit the germination of lettuce seeds and if they effect seedling growth."

Here's a student experiment done by Nia Tilley's students at The Kooralbyn International School near Brisbane. She said:

This should be considered a good starting point. There is room for some good quantitative (numerical) testing. I would suggest that a number of dilutions of the alleopathic solution be made to see if there is a correlation between concentration and percent germination. You could also ask "what is the minimum concentration that will show an alleopathic effect?" I know it will be hard to establish a starting concnetration but it could be expressed as "g/mL" such that if 5 grams of lantana leaves were macerated with 10 mL water the concentration would be 0.5g/mL (or 50 g/L). Then you could do serial dilutions of this solution. Perhaps you could centrifuge the macerate, or filter it, so that you have a clear solution to start with. I wish I was doing it.

The symbiotic relationships between clams and turtle weed on Heron Island.

Heron Island is on the southern end of the Great Barrier Reef, Queensland, Australia. It seems likely that if turtle weed growth is determined at selected points along the reef flat on Heron Island then greatest growth would occur around largest clam due to the larger amount of nitrogenous wastes.

I am grateful to Year 12 Biology student Codi Baker-Lahey from St Andrew's Anglican College, Sunshine Coast, Queenlsand for her photos from her student experiment on turtle weed and clam symbiosis there. Please see photos below. I asked her if she saw any evidence of coral bleaching so far south and she said "I didn't see any coral bleaching which is a good sign".

In conclusion Cody said: "The hypothesis proposed was that: the largest Turtle weed ( Chlorodesmis fastigiata ) growth (as recorded by length, width and height measurements to find volume) will occur around the largest Small Giant Clams ( Tridacna maxima ) (as recorded by length, width and height measurements to find volume) because of the nitrogenous waste produced by the Small Giant Clams was supported by the data collected. It was predicted to be a direct relationship between the volume of Small Giant Clams and Turtle weed and a reasonably directly relationship was established. This relationship is modelled by the equation y = 0.0526x + 19.124 with an R 2 value of 0.8519."

Ethanol biofuel from green algae

Ethanol is used as an alternative fuel source and as a petrol additive. It burns cleaner than petrol and diesel and can be produced from (renewable) algae by fermentation rather than being extracted from non-renewable sources such as oil. Algae grow very simply, needing only water, sunlight and carbon dioxide to thrive. After the algae is harvested and treated to release carbohydrates, yeast is added to begin fermentation, which creates ethanol in a similar way that ethanol is produced in wine or beer. One of the major benefits of using algae to produce ethanol is that algae can be harvested day after day, unlike competing sources, such as corn and soybeans.

Algae can also nearly double in quantity overnight, if the conditions are perfect (see student experiment suggestion below). To achieve perfect growing conditions, producers must ensure that algae do not get too much direct sunlight, which can kill them, and that the growing environment is moist, has a constant warm temperature and has clean water with balanced salinity and the optimum pH. A good (but difficult) student experiment would to make ethanol by the fermentation of algae as it can be done at home or in the lab.

There are many variables to consider in maximizing the amount of ethanol produced: type of algae, conditions (temp, sunlight, pH, water salinity), time before harvest (= money), type of yeast and added nutrients. How do you measure the amount of ethanol produced by distillation (density, volume, mass)? Choose one or two (at the most) variables to manipulate and control the rest. Plenty of websites available (note: biodiesel fuel from algal oil is a different process and probably too hard for senior biology). Students may find that a lot of time has to be spent understanding algae fermentation and this may make this student experiment too time-consuming. Nevertheless a Australian Government report on these variables can be downloaded here: Biohydrocarbons from Algae .

Growth of algae The algae present in lakes depends on whether the water is fresh or salty and whether it is poor in nutrients or rich in nutrients. There are two approaches to doing an student experiment on this topic. One (involving manipulating variables) is to grow your own and and measure density, volume and mass (or whatever you choose as an index of growth) at different stages under different conditions. With those results, you can talk about the optimal growing conditions for a real-life situation such as a biodiesel and ethanol biofuel farm (an important part of the "Evaluating Biological Issues" criteria). For some good background information the Australian Government report on these variables can be downloaded here: Biohydrocarbons from Algae .

To help you get started, here are a few suggestions about factors affecting growth:

Algae type: two algae often used are the slow-growing filamentous algae Spirulina sp, or the fast-growing single-celled Chlorella sp. Light: algae can grow at higher light intensities than normal daylight (even in Northern Australia) but can take up to 4 weeks to acclimatise to high light. The degree of mixing, and the length/depth of a pond affects how much light get to the cells. Temperature: Each species has an optimum temperature, but they can tolerate up to 15°C lower than this. However, sometimes just 2-4°C higher than optimum can be toxic. Oxygen: oxygen is produced by photosynthesis but high levels are a major inhibitor. Carbon: CO 2 is essential for algaal growth but some species can use the hydrogen carbonate ion HCO 3 - . None, however, can use the carbonate ion CO3 2- . These three species all exist in equilibrium and the ratios are affected by pH. pH: Algae can tolerate pH up to 11 but the CO 2 availability is affected at high pH. Generally, all is okay with pH<8 although the higer the pH the better it is at killing pathogens (especially if you are growing algae commercially in wastewater, such as from a pig farm). Nitrogen: nitrogen is abundant in wastewater but if you are adding it as a variable then you can use nitrate NO 3 - , urea, or ammonium ion NH 4 + as sources. Algae prefers the ammonium form, although high ammonium levels are detrimental. Please note: ammonium ion NH 4 + and ammonia NH 3 are different species and should not be confused. At high pHs, the equilibrium shifts towards the NH 3 form which is quite toxic. But ammonium levels over 200mg/L are detrimental to some algal species. The effect of ammonium/ammonia species on algae is little understood so here's your chance of fame. Phosphorus: limiting P reduces growth whereas an excessive P concentration is not a problem. However, high P levels are toxic. Note that at high pHs, phosphorus can precipitate as phosphates and not available for growth. Trace elements: S, Fe, Mg are needed but are not toxic in the amounts found in normal wastewater. High levels may be though.

Click Project 2-1 for Prof. Jennifer McComb's resource sheet. Note again: this second type of student experiment does not involve manipulating variables (unlike the first suggestion); instead it relies on natural variation. It is sometimes called a "correlational study".

Smart waste solutions with algae Want a real challenge for your student experiment and want to do something good for the world?  Here's an idea. Every year, huge blankets of algae - some larger than Sydney Harbour - spread along the Shandong coast between Shanghai and Beijing in China - the by-products of fish farms. Although not toxic, the blooms block sunlight and suffocate marine life. It costs the Chinese government around $250 million every year to clear its seas using chemicals to break down the blooms.

The Chinese asked a Queensland company - MBD Energy - to develop a technique to harvest the Shandong algae and to turn it into biochar – a soil conditioner – which could fertilise the ground in the region naturally. The process would reduce use of synthetic fertilisers, cut costs and reduce water pollution. MBD Energy has a research station at Pacific Reef Fisheries, Ayr, in Queensland, where scientists are using biological processes to clean up wastewater from prawn farms. They draw on the expertise of James Cook University (JCU) algae researchers, Associate Professor Kirsten Heimann and Professor Rocky de Nys.

In the process, the system produces tonnes of algal oils, nutrients for animal feed and other valuable by-products, including plastics and potential new pharmaceuticals. The remediation of industrial wastewater alone is a multi-billion dollar industry and market. The researchers are more optimistic than ever about the role algae will play in helping to meet growing demand for energy, food and clean water.

The question is "how do you turn this into a viable Biology student experiment?" You could look at one of their papers to see if there are some possible ideas. Start with Professor de Nys's article at https://research.jcu.edu.au/portfolio/rocky.denys/ particularly the one titled "Algal biochar enhances the re-vegetation of stockpiled mine soils with native grass".

Growth of algae A good experiment suggested by Kathryn Gardner for a Biology student experiment is on the rate of photosynthesis in algae. She says that "all of these experiments have worked well for us in the past". The link takes you to some experiments on Algal Jellyballs that was produced by Science and Plants for Schools (SAPS).

Green algae photosynthesise in a way similar to that seen in higher plants. In this practical, students use algae to look at the rate of photosynthesis. Since algae are tiny and are difficult to work with directly in the water, the first part of the practical involves 'immobilising' the algae as algal balls. This effectively traps large numbers of algal cells in 'jelly like' balls made of sodium alginate. Sodium alginate is not harmful to the algae, and they will continue to photosynthesise once immobilised.

Microalgae Biology teacher Ivy Walsham has suggested independent variables worth considering for an student experiment using microalgae:

- effect of light intensity on growth of microalgae - different coloured light on growth of microalgae - effect of carbon dioxide - effect of nutrients (change nitrate, phosphate etc) - effect of micro-nutrients like vitamins.

She says "Culture the microalgae in test tubes and record the daily growth. You can use a haemocytometer for counting the microalgae. If you culture under ideal conditions for 10 days you will get a graph similar to bacterial growth (exponential  graph). The pure cultures of algae are available from CSIRO. You can maintain the algae for a long time in the laboratory by sub-culturing it in agar plates."

Effect of copper on the growth of algae

The last thing you want in your swimming pool is algae - the green plant that grows on the walls and bottom of the pool. There are several ways to control it: keeping the sanitizer (chlorine) levels correct helps but often a copper-based algicide (algae killer) is used. The copper ion (Cu 2+ ) is a very effective algicide to both kill and prevent algae formation. Swimming pool companies say that about 0.03 to 1.0 mg/L (0.03 to 1.0ppm) of free copper ion must be present to be effective and safe.

The word "free" is used because "bound" copper (copper is tied up in an insoluble form) is not available to work as an as algicide. For non-biological systems (where no living plant or animal is present) a continuous level of 1.0 ppm is enough to assure effective algae control; more is superfluous and may damage surfaces and equipment. The toxicity of copper to algae has been the subject of a number of studies over the past 40 years because of its widespread use for the control of algae in natural waters. This suggests a good student experiment.

You could try growing algae in solutions with different copper ion concentrations from say 0 to 1 ppm. One problem you will have to sort out is how to measure the amount of algae in the samples. Perhaps it can be done using a spectrometer, or by measuring the depth at which you can just see a black cross appear/disappear (like in a simple nephelometer tube, or like the Secchi Disk method for turbidity in natural waters).

Safety note: copper is a heavy metal ion and is considered hazardous. It is important that you become aware of the risks. Care should be used when handling this product.

An interesting study by Drs Jenny Stauber and Mark Florence from CSIRO's, Division of Energy Chemistry, Lucas Heights Research Laboratories, Sydney, Australia found that copper ions depressed both cell division and photosynthesis in many species of algae notably the common freshwater green alga, "Chlorella" ( Chlorella pyrenoidosa ). They suggested that ionic copper toxicity may result from an intracellular reaction in which copper suppressed mitosis. In addition, they said that copper inhibits the enzyme catalase and reduces cell defence mechanisms. Reference: J. Stauber and T. Florence, 'Mechanism of toxicity of ionic copper and copper complexes to algae', Marine Biology 94, 511-519 (1987).

In their experiment they maintained Chlorella pyrenoidosa in MBL medium on a 12 hour light: 12 hour dark cycle (Philips 40 W fluorescent tube, white, 6500 K - see photo below) at 21ºC. They found that a Cu 2+ concentration of 7.9 x 10 -7 M (5 x 10 -5 g/L, equal to 0.05 mg/L or 0.05 ppm) gave a 50% reduction in growth. Click here to see what the MBL medium consists of (this may be too complicated for high school student experiment). One question you need to sort out is how to measure algae growth (perhaps measure the absorbance in a spectrometer). If you don't do Senior Chemistry you may need to brush up on your formulas for amounts and concentration.

The copper sulfate your school lab has is most probably copper sulfate pentahydrate (CuSO 4 .5H 2 O). It has a molar mass of 249.5 g/mol. Copper itself has a molar mass of 63.5 g/mol. Thus, to make a 1000 mg/L Cu 2+ solution (1000 ppm) you would have to weigh out 1000 x 249.5 ÷ 63.5 g of CuSO 4 .5H 2 O per litre of distilled water (3.929 g/L). Make sure you use distilled water as tap water will go cloudy. You can then do serial dilutions (1:10) to reduce this to 100, 10, 1, 0.1 ppm Cu 2+ , and from there you can make the solutions you want.

Effect of pH on the toxicity of copper algicide

Stauber and Florence (see above) found that at pHs below 7.0, the toxicity of copper is greatly enhanced. This suggests another student experiment whereby you prepare solutions of desired pH by diluting some 0.1 M hydrochloric acid (pH 1). A ten-fold dilution should increase the pH by 1 (approximately), so a 0.01M solution has a pH of 2 - check with a pH meter. To each of these add the right volume of a standard copper solution to end up with a known concentration of copper - say 1 ppm. You may have to read up on pH, strong acids and dilutions.

Effect of other metals on the toxicity of a copper algicide

Toxicity of ionic copper on algal growth is known to be reduced by trivalent (3 + ) metal ions in the growth medium, including those of Mn, Co, Al, Fe and Cr which form a layer of metal (III) hydroxide around the algal cell, adsorb ( not a b sorb) copper and reduce its penetration into the cell. The degree of insolubility of the metal (III) hydroxide is related to its ability to protect against copper toxicity. That's another variable you could try. Probably best to choose one of two metals and try a few different concentrations (keep the Cu 2+ concentration the same).

Effect of availability of copper on the toxicity of a copper algicide

When you look at algicides in a pool shop, they most likely will have two types of copper-based solutions for sale: a 5% CuSO 4 solution (5 g CuSO 4 .5H 2 O/100mL) and one that is an organic complex of copper - usually called "chelated" copper (about 7% Cu). These copper complexes ( such as copper alkanolamine complex) are said to be more toxic to algae than ionic copper because both the metal and the ligand (organic part of the molecule) are introduced into the cell. They are also more resistant to changes in pH. For an student experiment you could compare the algicide ability of both forms at the same concentration of Cu 2+ , and compare them at different pHs.

Enhancing the growth of algae with copper micronutrient

In addition to being toxic at relatively high levels, copper is (surprisingly) also an essential micronutrient for algae at very low concentrations. However, the levels are in the order of parts per billion and probably outside the scope of a high school student experiment. Interesting research by Stanley Manahan and Michael Smith of the Department of Chemistry, University of Missouri-Columbia, USA, titled 'Copper Micronutrient Requirement for Algae' is reported in Environmental Science and Technology , Vol. 7, no. 9, September 1973, pp 829-833).

Liquid seaweed extracts

Scientific opinion on the beneficial effects of seaweed extracts on plants range from dismissal as "muck and magic" to cautious acceptance (Abetz, 1980). Unscientific opinion is often wildly enthusiastic and claims all sorts of wonderful effects. Liquid seaweed extracts are sold in garden shops under weedy names like Seasol, Marinure, Maxicrop, Algistim . Scientific analysis has shown that the beneficial effects are unlikely to be from the mineral nutrients in the extracts but possibly come from hormones or other organic substances included in the extract.

Claims are made that seaweed extracts affect plants in the following ways a) increase frost resistance, b) increase resistance to fungal disease, c) increase resistance to insect attack, d) result in higher yield, e) deeper root penetration, f) increased nutrient uptake, g) better shelf life of fruit and vegetables. A good student experiment might be to investigate these factors, however, it would not be possible for you to investigate a), b) or f) in an acceptable way but other features are open to experimentation. Alternatively, you might try something new like the effect on keeping qualities of cut flowers. Click Project 2-2 for Prof. Jennifer McComb's resource sheet.

Life cycle of mosses

Little is known about the relative importance and timing of the parts of the life cycle of most Australian mosses. The sort of details that are required are the times of spore discharge, growth of the protonema, leafy gametophyte production, sex organ production (archegonia and antheridia), fertilization, growth of sporophyte, relative importance of reproduction by spores or gemmae and tubers.

Decide how much time you want to spend in the four possible areas of activity - field observations, spore culture, cultivation of gametophytes, experimental investigation of spore and leafy gametophyte growth. Where are you going to get information on local temperatures, day length, rainfall etc. to relate to your life cycle observations? Click Project 3-1 for Prof. Jennifer McComb's resource sheet. Note: this student experiment does not involve manipulating variables; instead it relies on natural variation.

Germination and growth of moss spore

s It is fairly simple to grow moss spores under sterile conditions. In time, leafy gametophyte may grow from the protonoma. You might like to try to grow spores of various Australian mosses about which little is known. Alternatively, you could pick one that is easy to grow like Funaria hygrometrica (Club Moss) and conduct experiments to determine what controls germination, growth, differentiation of leafy gametophytes etc. An student experiment such as this will depend on what time of the year you do it. Mature spore filled capsules are mostly available in the latter half of the year and ones collected in February, March often are hard to sterilize. Glasshouses may be a source of 'out of season' capsules. What will you look for as an early sign of leafy gametophyte development? How might you count the numbers of spores per capsule, per culture, or the number of leafy gametophytes that form? Click Project 3-2 for Prof. Jennifer McComb's resource sheet.

Bulbs that pull themselves down into the soil

Some plants have contractile roots that pull the bulb down into the soil. Oxalis (sour sob) does this, but the published work is on American species and it would be of interest to know how the local weed species ( Oxalis pes caprae ) behaves before designing eradication programmes. This suggests a possible student experiment. Are you going to use bulbs of one particular size or compare burial rate/final depth of bulbs of different size classes? How does the final burial depth and switch over from vertical to horizontal contractile roots compare with depth of bulbs in the field? Click Project 4-2 for Prof. Jennifer McComb's resource sheet.

Root responses to gravity

As you know roots grow downwards and if tipped sideways will curve over to point downwards again. This is called geotropism . There are lots of fairly conventional experiments you can do to find out which part of the root bends, if bending occurs if the roo tip is cut off, the relationship between the outward force and gravity etc. However for an student experiment you may wish to do something more difficult.

It is known that the first root that comes out of a seed (the radicle) is strongly geotropic. Lateral roots must be less so. Can you measure the strength of geotropism in a radicle and compare it with that seen in 1 st order, 2 nd order laterals? Is there any difference between plants that have a taproot compared to a fibrous root system? If you cut off the tip of the radicle when it is about 2 cm long is the strength of geotropism altered in the side roots if you measure it about a week later? How will you measure curvature? How are you going to measure "strength" of geotropism? How are you going to hold the seedlings vertical till you're ready to start the experiment? Click Project 4-3 for Prof. Jennifer McComb's resource sheet.

Root parasitism by the Christmas Tree

The West Australian Christmas tree Nuytsia floribunda is a "hemiparasite". Although it has green leaves and apparently normal roots it is unable to live unless it makes connections with the roots of other plants from which it sucks nourishment. The connections are called haustoria and a possible student experiment would be to discover what stimulates the Christmas tree roots to make haustoria. Other hemiparisites are found in Queensland and these may be suitable for this investigation. Trees are apparently not very selective as they have been known to latch hopefully onto underground electric cables. How will you select the place in the field to bury your objects? How will you find the stuff you bury in several months' time? Are you going to have one harvest or several? Think carefully about your experimental design so that you will distinguish between substance, shape in cross section and diameter of your test objects. Click Project 4-4 for Prof. Jennifer McComb's resource sheet.

Rooting of cuttings

Propagation of plants from cuttings is important in the horticultural industry and there is a continual search for compounds that will improve the success rate with rooting cuttings. Auxin hormones which induce root formation are available commercially. It has been found that commonly used fungicides may have a stimulatory effect or a depressing effect on root production when used along with the rooting powder.

For an student experiment you might like to examine the effect of these chemicals on some exotic and native plant species. For interaction experiments like these you have to be extra careful about your design. There may be several 'control' treatments necessary. How are you going to score rooting? Can you devise a quantitative scheme that will convert observations like 'poorly rooted' and 'many vigorous roots' to numerical values allowing a mean to be made of all cuttings for one treatment? Click Project 4-5 for Prof. Jennifer McComb's resource sheet.

Tolerance to waterlogging Plants

vary in their ability to survive periods of waterlogging. Species differ, and within species some strains or cultivars are superior to others. Observe which plants have survived in waterlogged areas in your district, and those that are abundant on well drained sites. You could do an student experiment to show whether or not species found in waterlogged conditions can in fact survive waterlogging better than others. At what stage of growth are you going to flood the plants; to what depth? For how long? How are you going to measure recovery, growth, yield and so on. Remember, a plant has both above and below ground parts. How many harvests are you going to make? What other soil or water parameters might you measure during your experiment? Click Project 4-6 for Prof. Jennifer McComb's resource sheet.

Effect of seawater and/or detergents on plant

s Plants that grow along the beach can tolerate the salty ocean spray that blows onto their leaves. They may however be severely damaged or killed if any detergent gets into the water. The question is what would happen to your local beach plants if the sea water was polluted with detergent? The beautiful Norfolk Island Pines around Sydney beaches like Bondi and Maroubra were killed as a result of the detergents in sewerage released in the ocean (see Pitman, MG, Dowden HGM & Humphreys, FR 1977, 'The outfall connection: the plight of our coastal trees', Australian Natural History , vol. 19, no. 3, pp. 74-8).

Plants that grow around river estuaries that go salty in summer could also be investigated. Having observed the effects of an experimental salty spray and which plants are most sensitive you might check out plants near your local ocean sewerage outlet. It is important to know how the sewerage is treated as different treatment methods reduce the amount of detergents that remain. Will you treat the plants with detergent in straight sea water or diluted sea water? How often will you treat? How will you mark the treated leaves, prevent spray drift, score the damage? What will be your control? Is there any way of measuring the salt the plants get in the field in addition to your experimental sprays? Click Project 4-7 for Prof. Jennifer McComb's resource sheet.

Effect of coal seam gas water on plant

s Coal seam gas is an important energy resource in Queensland and production of this gas now makes up an increasing proportion of Queensland gas demand. Coal seam gas is natural gas - a mixture of predominantly methane and other hydrocarbon gas compounds. It is bonded (through geological and hydrological pressure) to microscopic surfaces (described as cleats or fractures) of the coal. It is effectively held (adsorbed) in the coal by burial pressure and water. Coal seam gas producers drill numerous wells into the coal seams below the surface to extract the gas.

The Queensland Government acknowledges that landholders face increasing pressure for access to their land for gas and other resources exploration and development. Water is a primary by-product of CSG development. The quality of the water ranges from potable to saline and may be rich in other constituents that make it unsuitable for many uses. The rapid expansion of the coal seam gas industry in the rich farming region of the Surat Basin (Darling Downs) may poses significant risks to agricultural production and water supplies where agricultural production in the Surat Basin is worth $1.5-2 billion. The coal seam gas industry is likely to drill up to 40 000 wells in Queensland by 2030, taking a minimum one hectare each of prime agricultural land each.

Yet many people believe that there are many unanswered questions about its broader impacts which have alarmed farmers who fear that their livelihoods and the country's food security may be put at risk. The water that comes out of the coal seams contains a lot of salt, something like five to eight tonnes per megalitre and up to 2.8 million tonnes of salt could be brought to the surface by coal seam gas mining to impact local prime farm soils. This seems like an ideal topic for an student experiment. You may like to find out what chemicals are in coal seam gas water and investigate their effect on the growth of plants (but don't even consider the BTEX carnicogens benzene, toluene, ethylbenzene and xylene).

Movement of plant stems

The growing tip of a stem does not grow directly vertically but moves upwards in a helical path. The question is whether there is a difference in the magnitude of the movement (called circumnutation ) in shrub plants and twining climbers. What environmental factors affect the movement e.g. will it continue in complete darkness? What happens if a piece of vertical fencing wire is placed in the path of a twining stem of leaf tendril? Darwin's method of examining circumnutation works well even though it is 100 years old! The idea is to mount a sheet of glass about 10 cm above the plants and to line up the apex and put a spot on the glass.

Doing this every couple of hours gives you a record like that in the diagram of the plant's movement. What do you think causes the movement of the tip? How will you be sure wind, drought etc. are not affecting your plants? How are you going to quantify the magnitude of the movement? How will you be sure that phototropism is not affecting your experiment? Can a given twining plant climb around supports of different sizes? What is the critical cylinder radius above which a plant is no longer able to twine? What is the effect of friction in the vine ability to grasp the pole? Similarly, what is the pressure generated by a plant on the pole? Click Project 4-9 for Prof. Jennifer McComb's resource sheet.

The figure below on the right (below) has been taken from "Mechanics of Climbing and Attachment in Twining Plants" by Alain Goriely and Sebastien Neukirch, Physical Review Letters 97, 184302 (2006) - click here to get an extract.

Floral clocks

The timing of flowers opening and closing and of pollen shed is well known for European and horticultural plants. In fact Linnaeus in 1748 made a floral clock in his garden so that you could roughly tell the time of day by sstudent experimentng which flowers were out! Similar information is not available for most Australian wildflowers. Some species have flowers open only once, others several times. Do learn about the structure of a daisy "flower" before tackling these. For some species like Hakeas and Banksias with spikes of flowers the number of newly open flowers as well as the time of opening is of interest. What might control time of flower opening and pollen shed? Do you expect differences in opening time on cooler days, wet days, and overcast days? Do you expect any difference in time of pollen shed between flowers pollinated by bees or moths, or wind? Click Project 4-10 for Prof. Jennifer McComb's resource sheet.

Wind borne pollen

Pollen carried by wind can be taken to very high altitudes or hundreds of miles out to sea. However the distance from the parent plant that most of the pollen actually gets may be surprisingly small. Selecting a pollen source is the difficult bit. It must be a plant that sheds lots of pollen and the pollen must have a distinctive shape. There must be no other plants of this species in the area. Neither can there be plants of another species with a similar sort of pollen in the area.

A suitable plant would be a pine tree (an introduced plant) on a farm with no other pines around; a patch of Juncus (rush) in a wet spot with no other rushes (or bulrushes) around etc. Are you going to expose slides only on the windward side of the tree or on all sides. How are you going to arrange to have slides exposed all at the same time? For how long will you expose slides? Will you shut down your experiment if the direction of the wind changes? What environmental factors will you monitor while the slides are exposed? Click Project 4-11 for Prof. Jennifer McComb's resource sheet.

A pollen calendar

Pollen in the air may cause hay fever in susceptible people. For this reason in spring and early summer, daily pollen counts are carried out in some cities and the results published in newspapers and on the internet. For an student experiment you could compare published data with what you can collect in your own district. Pollen can be collected by the gravity method - expose slides coated with vaseline for one day. What other "objects" apart from pollen might you expect on your slides? How are you going to identify the pollen you find? Could a local doctor or hospital give you data on frequency of onset of asthma to correlate with your pollen counts? Perhaps you could investigate and compare the accuracy of various methods. Click Project 4-12 for Prof. Jennifer McComb's resource sheet. Examples of pollen calendars for Queensland and Australia can be seen at http://www.weatherzone.com.au/pollen-index/qld/brisbane/brisbane and an allergy calendar at http://www.allergy.org.au/content/category/3/48/241/

Pollen in honey

Some people claim they are allergic to honey because of the pollen it contains. During spring, bees flit from flower to flower and collect nectar, inadvertently collecting pollen from the flowers they've visited along the way. The honey that they produce will therefore contain some of these pollen. Honey is sometimes sold with the different flavours kept separate (e.g. karri, white clover etc.) but more often as a blend. The question is whether different sorts of honey have a distinct range of pollen types. Note, however, that commercially produced honey may not contain pollen as these are filtered prior to bottling. Honey from small backyard producers are your best bet.

A study by Helbling and co-workers (reference below) showed that 75% of honey-allergy sufferers were sensitive to dandelion honey. For an student experiment would you just score presence or absence of various sorts of pollen or are you going to estimate frequency as well. How are you going to identify the sort of pollen that you find? (it may be impossible, in which case good drawings should be made). Are you going to "stick" to local pollen or look at some from overseas as well. Click Project 4-13 for Prof. Jennifer McComb's resource sheet. Note: this student experiment does not involve manipulating variables; instead it relies on natural variation. See "Allergy to honey: relation to pollen and honey bee allergy" by A. Helbling, et al, Allergy , V 47, No. 1, pages 41–49, February 1992.

What causes the death of annual plants?

Some trees live for thousands of years but at the other end of the scale annual plants die after a year or less - why? It is not fully understood but it is known that you can extend the life of annual plants by removing the fruits. A good project would be to investigate how long you can extend the life of the plant if you remove the flower buds; the flowers after pollen is shed, the young developing fruit, the immature fruits, the mature fruits? However, this may take to long to carry out and only be successful if you began earlier than the rest of your class.

As a related issue you might compare the total yield of fruit from your plant if you remove fruit as it matures rather than do one harvest when the plant dies. Plants like legumes or tomatoes which flower on side branches are suitable to use, but you might also like to include something like sunflower in which the top growing point is "used up" in producing the inflorescence. Click Project 4-15 for Prof. Jennifer McComb's resource sheet.

Seed germination

The environmental conditions that stimulate seed germination are poorly understood for many Australian native plants. For an interesting student experiment you could investigate the conditions needed for germination of several related species, particularly those with horticultural value. Hint: select species for which you can obtain large number of seeds so that you can have a good experimental design. Try and find out when the seeds germinate in the field as this might help you determine the most likely treatments to use. Avoid using orchids as they may have very special requirements like a suitable fungus being present.

Factors to investigate include: hard seed coats (common in legumes); an impermeable seed coat (prevents water uptake); germination inhibitor (causing dormancy) - some seeds contain substances that prevent germination and these inhibitors are leached out over a period of time (maybe years); temperature requirement (many seeds will germinate only at a particular temperature); light requirement (some seeds require light to germinate (often fairly small ones) or just the opposite - they won't grow except in the dark. Think carefully about how many factors you can test with the number of seeds you have in hand. Click Project 4-18 for Prof. Jennifer McComb's resource sheet.

Dispersal of plants in clothing, towels and rugs

Humans may unknowingly carry around weed seeds particularly if they have brushed past plants or gone for a bushwalk. Surely you've walked through long grass and found your socks covered with Cobbler's Pegs which you've picked out at home and disperse. Pretty clever seeds!

Interesting research has been done by Ken Scott from the School of Environmental and Life Sciences, Charles Darwin University (reference below). He investigated the potential of Gamba Grass ( Andropogon gayanus ) seeds to be dispersed unintentionally attached to the clothing and backpacks of four people while performing field work in a Gamba Grass-invaded savanna in northern Australia. Gamba Grass seeds attached to, and were carried by, each subject during the course of field work. One person carried 65 seeds, while another carried just eight. They stuck to water bottles, and in the crevices of shoes and socks, rather than on the exterior of clothes.

This suggests an interesting topic for an student experiment and it would be worth reviewing his journal article. Perhaps you could look in or on shoes and boots, stuck in tread or on shoe laces; in socks, trouser cuffs and pockets, on coats (particularly sheep skin coats), beach towels, travel and picnic rugs car floor mats and car carpets. Maybe a friend living in a country area will clean his door mat for you and send you the specimen (it is illegal to send soil specimens interstate).

Reference: Kenneth A. Scott, Ecological Management & Restoration, 2009, Vol. 10, No. 1, pp. 71-73. Click to download .

Dispersal of plants by vehicles

Vehicles may carry seeds in cracks or in mud and provide a threat to quarantine barriers. For example, cars brought in from overseas are steam cleaned before being delivered to their owners. You could survey the seeds/plant material carried by a range of vehicles. You could compare what is caught in say tyre tread of different vehicles or you could deliberately wash a vehicle thoroughly before a long journey, or a journey through a scrubby area and then wash it again afterwards. How will you identify what grows? How will you know if everything has germinated? How long will you wait for things to germinate? Click Project 4-20 for Prof. Jennifer McComb's resource sheet.

Germination and establishment of mistletoe

Mistletoe seeds are easy to germinate but adult plants occur on a restricted range of hosts. Is this because seeds never get deposited on other plants? Or if seeds do arrive on other plants, how big does the hopeful mistletoe grow before it is prevented from attaching? The common mistletoe Amyema preissii is found mainly on Acacia but also on Cassia and Eucalyptus . This project is particularly suitable for students living in the wheatbelt of Western Australia where heavy infestations of Acacia acuminata occur but could be adapted for other species and locations. Click Project 4-21 for Prof. Jennifer McComb's resource sheet.

Competition between weeds and desirable plants

Everyone hates weeding the garden. It is known that weeding vegetables during the early weeks of their growth gives a big increase in final yield, but that weeds established after a certain time have little effect on yield. That suggests an interesting student experiment: could you find out when you can hope to stop weeding your vegetables? There are two ways of tackling this. You might plant the vegetable seeds and let the local weeds do their thing, or you might start in weed free soil and deliberately plant weed seeds at a certain density at specific times. The second approach gives a better experimental approach as you can control density of weeds. Click Project 4-22 for Prof. Jennifer McComb's resource sheet.

Competition between Introduced and Native species

This is a fascinating student experiment developed by my colleague Adam Delroy at Moreton Bay College for a Year 10 Technology and Applied Science (STEM) course but equally suitable for a Year 11 Biology project. It is based on the research by Jennifer Firn, Yvonne Buckley and others at QUT Brisbane.

It concerns the threat posed by the introduction of invasive plant species, including grasses, into the prairies, steppes and savannahs across the planet. To counter this it is imperative that scientists greater understand the competitive interactions of natives and invaders. A quarter of the Earth is covered in grasslands. They are highly endangered ecosystems. There are examples of invasive species affecting native species by competitive exclusion and ultimately extinction. The problem is worsened by global warming which will lead to atmospheric CO 2 enrichment, climatic warming, rain addition and atmospheric nitrogen deposition. Different plants are differently susceptible to these factors.

In this study, the researchers measured competitive interactions among an invasive grass and two Australian native grasses that are functionally similar and widely distributed. They conducted a pair-wise glasshouse experiment, where they manipulated both biotic factors (timing of establishment, neighbour identity and density) and abiotic factors (nutrients and timing of water supply). They found that the invader significantly suppressed the performance of the natives; but its suppression ability was contingent on resource levels, with pulsed water/low nutrients or continuous watering reducing its competitive effects. The task we developed at MBC involved the competition between the natives Microlaena stipoides , (weeping grass) or Elymus scaber , (wheat grass) and/or invasive ( Eragrostis curvula , african 'lovegrass' grasses to better understand the biotic and abiotic conditions for survival/competition. The research questions the students asked were:

BIOTIC FACTORS 1. Is the invasive supressed or facilitated by the presence of the native (using continuous water/high nutrient)? 2. Is the native supressed or facilitated by the presence of the invasive (using continuous water/high nutrient)? ABIOTIC FACTORS 3. Do either invasives or natives prefer pulsed water or continuous water? 4. Do either invasives of natives prefer high nutrients? The results were fairly ambiguous but next year we will modify the design. The task sheet can be downloaded here . A copy of the Firn et al Oecologia paper can be downloaded here .

Growth of weeds

Many persistent weeds owe their nasty reputation to their ability to regenerate from either seeds or from vegetative structures and to their ability to grow up from considerable depths. For an student experiment, you might investigate for example the depth from which bulbs of Oxalis (sour sob) or runners of kikuyu grass, etc. will emerge. Alternatively, you might investigate how small a piece of couch, veldt or crab grass is sufficient to establish a new plant.

Although weeds are very successful in your garden, for experimental purposes it is better to grow them in pots or seed trays so you can control the experimental conditions more easily. How are you going to standardize the material you start with - bulb weight, size, number of nodes on a runner, its length? Are you going to leave existing roots and leaves on or cut them off etc.? If taking small bits off a runner it may be important to note the physiological age i.e. how far back from the apex a particular piece is taken. Click Project 4-23 for Prof. Jennifer McComb's resource sheet.

Ecological effects of plant chemical

s It has been known for a long time that some plants grow well together while in other cases one plant seems to prevent the growth of another by the chemicals it produces. This is termed allelopathy . An interesting student experiment would be to find whether there is a scientific basis for the observation that various species of plants can inhibit the growth of other plants. Organic and inorganic substances including growth regulators can be leached from the leaves or roots of plants by rain, influencing the growth of nearby plants of the same or different species. Volatile substances are also known to be effective. Plants that are affected can be of the same species and/or different species. Insects too can be repelled.

There is much non-scientific literature on companion plants, and some of these observations might be explained by allelopathy. However, studies by CSIRO concluded that allelopathy is likely to be a cause of understorey suppression by Eucalyptus species especially in drier climates (reference below). How will you first prove that allelopathy exists in your system? How will you then find out where the toxin is coming from? Click Project 4-24 for Prof. Jennifer McComb's resource sheet. Reference: An Assessment of the Allelopathic Potential of Eucalyptus, FE May and JE Ash, 1990, Australian Journal of Botany 38 (3) 245 - 254.

Litter decomposition

The breakdown of leaf litter is an important part of the cycling of nutrients in the ecosystem. You could do some experiments to relate the rate of decay of leaf litter to the nature of the plant tissue involved, the soil organisms present and the soil water supply. The succession of fungi associated with the decomposing leaf litter of Eucalyptus regnans was studied by the CSIRO in order to relate the degree of decomposition of the leaves to the mycofloral population. Species of Coelomycetes and some Moniliales were the important initial elements of the mycoflora in the litter, but species of Penicillium and Mucorales succeeded them on leaves in advanced stages of decomposition.

For an student experiment you could use leaf tissue of contrasting types - Eucalypts, pines, Banksias, and herbaceous plants like cape weed, clovers, grasses etc. How will you study the "nature" i.e. hardness of the plant tissue involved? How will you get comparable initial samples of different species which have different shaped leaves? Click Project 4-25 for Prof. Jennifer McComb's resource sheet.

Marine environments

Each year many tonnes of leaves and wood from terrestrial plants are deposited in lakes and rivers and eventually carried out to sea. This suggests a good student experiment: you could study the rate of decay of various types of plant material under water. You may wish to compare the rate of decay of material submerged at different depths or buried in the substratum. It might be of interest to compare the rate of decay in an anaerobic stagnant swamp mud and a fast flowing clear stream. Click Project 4-26 for Prof. Jennifer McComb's resource sheet.

Litter under trees

Many people hate raking leaves off lawns so they plant evergreen eucalypt trees rather than deciduous trees in their gardens. It seems however, that eucalypts drop leaves, twigs, bark, flower parts and fruits in vast amounts and the gardener hasn't solved this problem. This is even greater when all the litter falls into a swimming pool and blocks the filter.

For an student experiment you might like to compare the seasonal occurrence of litter beneath eucalypt and deciduous trees (but recognise that this would have to be over a longer period of time than a normal student experiment). You may also compare pines. How many replicate trays should be used? Are you going to work in a garden situation or a native stand of eucalypts?

There is an interesting research article by Prof. Ray Specht and Yvonne Brouwer from the University of Queensland Botany Department entitled "Seasonal Shoot Growth of Eucalyptus species In the Brisbane Area of Queensland" in the Australian Journal of Botany, V 23, No. 3, 1975, pp. 459-474. The appendix contains data on leaf fall for many Australian native plants. Click here to read this appendix. Also, you can click Project 4-27 for Prof. Jennifer McComb's resource sheet. Note: this student experiment does not involve manipulating variables; instead it relies on natural variation.

Growth of isolated roots in sterile culture

Various parts of a plant are normally linked together - leaves, stems, roots, etc. but by growing the parts separately under sterile conditions it is possible to find out if each can grow independently, or whether it is dependent on material passed from other parts of the plant. You might like to try and get tomato roots to grow cut off from the top of the plant. Even to get the initial cultures growing well is an achievement but having mastered this you might like to investigate which tomato cultivars grow best, or to try using other plants. You could also compare growth in the complete medium compared with growth in distilled water, or water with 20% sucrose.

If you are preparing your own media you could investigate the effect of different levels of sucrose, or of leaving out the vitamins. Click Project 4-28 for Prof. Jennifer McComb's resource sheet. Click here for Jennifer's " Sterile Media " instructions.

Plant callus culture

As a plant grows the cells in various organs mature and stop dividing. However, under certain conditions such as wounding, some cells can be stimulated to divide and form a mass of disorganised (= undifferentiated) cells called a callus. This can be used in studies of plant biochemistry, mutation, regeneration of shoots and roots from the callus and plant breeding. You might attempt to grow a callus from the stems or roots of some plants in sterile culture. Carrot root is a good tissue to start with.

The method involves sterilizing the outside of the carrot then cutting out small pieces and placing them on a medium containing hormones that cause cells, particularly parenchyma and cambial regions to start dividing. Click Project 4-29 for Prof. Jennifer McComb's resource sheet.

Haybale fires

Over the warmer months Rural Fire Services throughout Australia are called to extinguish fires in stored hay as a result spontaneous combustion. These fires are usually the result of a combination of storing hay that is too moist and warmer temperatures. These fires can lead to the loss of valuable feed and stored machinery as well. The phenomena of exploding haystacks has been with us for as long as we have been making hay. Pliny, the Roman Philosopher wrote in 60BC "When the grass is cut it should be turned towards the sun and must never be stacked until it is quite dry. If this last precaution is not carefully taken a kind of vapour will be seen arising from the rick in the morning, and as soon as the sun is up it will ignite to a certainty, and so be consumed". Old microbiology books often contain anecdotal evidence of haystack explosions, one from 1939 states "The stack that sets itself on fire does so in a curious way dependent at first upon both moisture and microorganisms. A really dry stack of hay won't heat spontaneously; a really damp stack can't be set fire to".

Even though hay bales may seem dry, they are actually quite moist. Hay that is considered 'dry' has up to 20% moisture content. Although hay should be stored at about 15% humidity for the best conservation, it is often baled at much higher moisture levels. There are many reasons for this: moist hay has less leaf loss (major nutrients are in the leaves), sun drying reduces its quality, and, most importantly, climatic conditions often do not allow adequate drying.

When hay is bailed and the plant material is either too green or has excess moisture (over 30%, as a result of rain, dew, flood water, etc) it continues to respire, generating heat and water which emerges as a vapour through the leaf pores. Within the confines of the bale, the water condenses and spreads by capillary action.  This initiates and promotes fungal and bacterial growth in the bale. These micro organisms produce heat and along with higher external temperatures and humidity, and can reach a peak of 70°C at about 5-7 days. If the relative humidity in the middle of the stack is below 95% then the microorganisms become inactive and the temperature of the stack drops. If the relative humidity in the middle of the stack is above 97% then the resultant heat of vaporisation of the water dissipates the heat rapidly and the temperature of the stack drops. This explains why very wet silage does not explode. However if the narrow window of 95%-97% relative humidity is obtained then the microorganisms continue to produce heat, which cannot escape, which raises the temperature. This temperature rise accelerates the chemical oxidation of the hay releasing more heat quickly raising the temperature within the bale to ignition point (200-280°C) where it will burst into flames.

It all depends on the size and shape of the bale, the moisture content and how tightly it is packed. Even if it doesn’t catch on fire the presence of micro-organisms can be a health problem: a disease known as Farmer's lung disease - a pulmonary affection caused by an allergic reaction to the inhalation of these thermophilic actinomycetes and molds. Farmer's lung typically produces shortness of breath, cough, and fever. If not adequately treated, this disease can lead to severe and irreversible lung damage. This suggests a great student experiment and one with great social and economic importance.

A traditional method of monitoring hay stack combustion potential used by farmers has been to poke a section of steel rod into bales in the hay stack and leave for several hours before removing it and feeling for any heat build-up. But for an student experiment you have to do better than that.

However, if you are using a standard rectangular bale you can just push a thermometer in to it. For a big bale you would need to get a length of metal pipe with holes drilled in it and bash it into the bale – and then lower a thermometer (attached to a string) gently down the pipe until it is centered.

The most common bales used in Australia are the two string bales, which are approximately 900mm long x 450 mm deep x 350 mm high (16 kg). A prime shredded lucerne hay bale costs about $13.

MORE PLANT SUGGESTIONS

Many of the suggestions below involve rates of change (growth rate, germination rate, transpiration etc). You should read the note on "identifying variables" in the description of the "best conditions for growth of a plant" student experiment above.

• How does cold storage affect the germination of seeds? Possible factors: type of seed, length of storage, temperature of storage.
• The effects of wind speeds on the rate of transpiration of Tristaniopsis laurina
• The relationship between speed of germination and growth rate
• Allelopathic effect of eucalyptus grandis on the germination and growth of erica sativa. It may be hypothesised that allelopathic qualities of E. grandis will inhibit the growth of E sativa; thus soil samples taken from the base of E grandis will contain the highest amounts of allelochemicals.
• Pathogenicity analysis of Colletotrichium species isolates from strawberries and alternative hosts. It has been hypothesised that all the strawberry camarose plants excluding the controls, will exhibit symptoms of plant collapse, such as wilt within 4 weeks of being injected with Colletotrich species cultivated from 10 different isolates, providing that all environmental conditions are ideal for disease development, confirming the pathogenicity of the 10 isolates.
• Different planting depths will effect the germination rates of seeds.
• The relationship between the success of chitons and the rocky substrate they inhabit. Soil with higher soil to seed contact (silt) will have a higher germination rate than those in soil with less contact. It has been hypothesised that if the success of chitons was to be compared from a natural rocky substrate to an artificial surface then it is expected that there will be a larger population inhabiting the natural rock substrate due to shelter.
• Chemicals and/or factors affecting the maintenance/survival of cut flowers.
• Response times of sensitive weed under various environmental conditions
• Effect of household cleaners (other household chemicals) on the growth of plants….. including aquatic and terrestrial. Need to justify why they would have an effect.
• Finding the optimum concentrations of a hormone in growing tissue cultured plants
• Plants growing tips will bend towards light, and if the growing tip is removed, the tip will not bend How much of the tip needs to be removed?
• Effect of environmental conditions on the rate of transpiration of plants using a potometer
• The effect of humidity on the germination of plants, fungus, seeds
• The effect of duckweed on nitrogen levels in water
• The effect of light wavelength on the growth of lettuce
• The effect of a natural germination inhibitor on the germination of plants (different species)
• The effect of soil density/depth/structure/type, on the germination/growth rate of plants
• The effect of salinity on the germination of birdseed
• The effect of calcium on the germination of beans
• The effect of pH on the growth of duckweed
• The effect of temperature on the germination of duckweed
• The effect of gibberellins on the growth of roots
• Effect of gibberellins on vegetatively propagated plants … eg basil root growth
• The radishes in the closest proximity to the sweet potato plant will germinate and develop at a slower rate compared to the radishes further away.
• Effect of geotropism on the growth of plants
• Effect of phototropism on the growth of plants
• Determination of the amount of plant mass that needs to be removed to kill weeds
• Effects of ethylene on ripening …. Either ripe bananas or hormone
• Determine what effect if any, the amount of stored food has on the growth of potato buds (eyes)/cane billets/
• Comparison between vegetative propagation of plants and germination of seeds
• Investigate the various methods of seed distribution….. possibly find links between seed types and another factor like germination rates, method of germination etc How would drought affect the rate of photosynthesis in plant leaves?
• How would drought affect respiration in plant leaves?
• How does phototropism affect seedling growth?
• Does grey water/bore water damage root hairs? Make a time lapse video showing growth of root hairs
• Does grey water/bore water affect the rate of germination of seeds?
• Does detergent affect the rate of osmosis in plants?
• Are cell membranes damaged by washing powder?
• Which grass species will grow best in drought conditions?
• Do cacti lose any water in dry conditions? How do they survive?
• Eucalyptus leaves hang vertically in hot weather. Why is this? How could you prove the benefits.
• The rate of fall of, and distance travelled by, winged seeds in relation to their structure.
• Testing for salt tolerance or lead tolerance in races of grasses Growth of duckweed (Lemna species) at different levels of added nitrate and/or phosphate to simulate eutrophication.
• Growth of duckweed (Lemna species) at different levels of added detergent to simulate pollution.
• Population dynamics of plants in permanent quadrants; death rates of seedlings and mature plants.
• Birth and death rates of different leaves on the same plant or leaves on plants from contrasting habitats.
• Mineral nutrient requirements of plants; water and sand cultures. Tissue cultures of plants in sterile conditions on agar. The effects of different water regimes on plant growth.
• Inter-specific interaction between clover and grass; addition of fertilizer. Effects of various wavelengths of light, particularly red: far-red ratio, on seed germination, the tropic response of plants.
• Factors affecting aerial (adventitious) root growth in ivy. Light compensation points of sun and shade plants. Influence of different wavelengths of light on the phototropic response of plants.

CORRELATIONAL STUDIES INVOLVING PLANTS The following suggestions involve hypothesis-testing research questions not involving artificial manipulation of variables (relying more on natural variation of variables). This type of investigation is known as a "correlational study" as you you look for correlations between variables rather than artificially manipulating them.

• Compare the physiology of different species of leaves (mesophyll cells, stomates, chlorophyll distribution and density)... you may use a microtome to section specimens for microscope viewing. This could be tested with a hypotheses like:
• the higher up in a canopy, the greater the abundance of stomata due to an increased capacity to photosynthesise in the presence of a greater concentration of sunlight;
• the leaves at the top of the canopy will have less mesophyll as they are exposed to more sunlight and therefore would lose more water due to evaporation;
• plants which live in the understory will have a higher concentration of chlorophyll as they must utilise as much sunlight as possible which filters through the canopy.
• Are the stomates on all plants the same size? shape? distribution? Investigate with the Proscope.
• Do young leaves have the same density and distribution of stomates as older leaves? You could investigate with the Proscope. Possible hypothesis: The younger leaves of plants have less stomata due a reduced need for photosynthesis in new leaves.
• What controls the opening and closing of stomata on leaves? Use the Proscope to investigate this. Students could investigate the effects of concentration of sunlight on rate of opening, maximum size of opening and compared to different plants in different environments (rainforest to coastal leaves etc).
• Compare the reproductive structures of flowers, native - exotic; self pollinating - cross pollinating.
• Compare the chlorophyll in leaves from the top of the tree to the bottom of the tree (no manipulated variables).
• Comparison of stomata from plants adapted to different climates/microclimates (dry vs wet environment).
• Trees and grasses will contain different pigments in their leaves.
• Pollen counts, made by exposing sticky slides to the atmosphere on several successive days, correlated with weather data and hay fever suffering.
• Variation in the size of pollen grains in different species of flowering plants.
• The time and location of most active cell division in root tips.
• Thin-layer chromatography of flower pigments in closely-related species.
• Pollination; flower constancy of pollinating insects; pollen identification from insects; flower preferences in relation to tongue length; role of flies in pollen-eating and pollination.
• Mosses and algae on north-south sides of walls or different levels up a salt marsh; distribution pattern in relation to desiccation tolerance.

FUNGUS OPTIONS

Fungi play an important role in decomposing animal dung and recycling the nutrients it contains. The spores of these 'coprophilous' fungi are eaten along with the animals food, the fungal hyphae grow in the dung and fruiting bodies are produced on the surface of the pellet. Various fungi appear in succession. A good student experiment might be to investigate the succession observed on different kinds of dung. Alternatively, the fungi that grow on dung from a free running animal could be compared with those from a caged animal fed with pellets.

You might wish to determine which of the fungi are phototrophic (i.e. shoot their spores towards the light) or how far the spores of various fungi can be shot. Click Project 1-1 for Prof. Jennifer McComb's resource sheet. Note: this student experiment does not involve manipulating variables; instead it relies on natural variation.

Fungi that break down hair and nails and insect skins

Things like sheep horns, wool and hair, bird feathers, animal nails, insect skins etc., are of keratin and chitin. These are rotted away by fungi called keratinolytic and chitinolytic and a good student experiment might be to investigtae the abundance and rate of breakdown of such fungi in your local soils. Alternatively, you might want to study how fish scales rot away and do some experiments in fresh or seawater with aquatic sediments. How might you actually measure the rate of breakdown? How will you score the frequency of the various fungi so you can compare the different sources of soil? Click Project 1-2 for Prof. Jennifer McComb's resource sheet.

Isolation of fungi from soil Many fungi occur in soil

Some are saprophytic on animal and plant remains, others are plant parasites. A few trap and digest soil nematodes and other soil animals. In turn, the fungi are eaten by soil animals like springtails and mites. A good student experiment might be to isolate soil fungi and compare the frequency of different fungi from various types of soil? How will you check that the fungi you grow are actually from the soil and not from faults in your sterile technique? If you are hoping to estimate the number of fungi per gram of soil, at what stage will you weigh your sample? (You will use a lot less than 1 g). Are you going to sample soil from the same place at different times of the year, at different depths, or from a sequence of places along a transect, say from beach through sand dunes into forest, or from burned to unburned areas of bush?

Click Project 1-3 for Prof. Jennifer McComb's resource sheet. Note: this student experiment does not involve manipulating variables, instead it relies on natural variation.

Nematode trapping fungi

Several fungi in soil can trap and digest nematodes. Some of these fungi produce sticky hyphae or spores which become attached to, and eventually penetrate passing nematodes; other fungi produce ring traps that inflate on contact, or coiled hyphae in which the nematodes become entangled.

A good student experiment might be to grow nematode-trapping fungi and see them catch the nematodes? Are you going to examine one soil type in detail or look at different soil types; sand, compost, mud from gutters, mud squeezed out from mosses, rotting wood? Do you want to do some experiments on why the traps are only produced when there are nematodes present? Will dead nematodes stimulate development; will the liquid in which the nematodes have been growing stimulate development etc.? Click Project 1-4 for Prof. Jennifer McComb's resource sheet. Note: this student experiment does not involve manipulating variables; instead it relies on natural variation.

Freshwater fungi

Some mould fungi live on submerged decaying dicot leaves and produce non-motile spores (conidia) underwater. These fungi (aquatic hypomycetes) have been extensively studied in Europe and America but little is known about them in Australia. Once you have discovered a source of these fungi you might look at their seasonal abundance and their occurrence on different kinds of leaves.

Alternatively, you might compare their abundance in different sorts of habitats - fast flowing streams with tree lined banks (eucalypts and native plants or introduced willows etc.) swampy areas with some water flow (plants like Typha-bullrush and Juncus-rush), or stagnant ponds. How will you figure out from which plants your decaying messy leaves came? How will you distinguish aquatic hypomycete conidia from conidia of terrestrial fungi, moss and fern spores, pollen and so on? Is it possible to determine spore concentration in water by collecting foam or do you need running water for this? If you count spore numbers how will you back calculate to the volume of river water originally sampled? Click Project 1-5 for Prof. Jennifer McComb's resource sheet. Note: this student experiment does not involve manipulating variables; instead it relies on natural variation.

PROTIST OPTION

Slime moulds, like Physarum polycephalum are part of the kingdom Protoctista. This is probably the least understood of the five kingdoms of life. One of the most interesting things about Physarum polycephalum is that it shows a quality that could be called primitive intelligence. Studies done by Dr Toshiyuki Nagakaki and colleagues in Japan have shown that Physarum polycephalum can find the shortest distance through a maze. When the Physarum polycephalum organism is chopped up and dropped into a labyrinth (a maze), they put themselves back together and start to move. If a food source is placed at the entrance and exit to the maze, they avoid dead ends in the maze and form a connection (as a single tube) between the food sources.

In all cases, the Physarum polycephalum chose the path that was the shortest between the two food sources. In a way, it "solved" the puzzle of finding the shortest path through the maze! The paper was printed in Nature V407, 28 Sept 2000, p 470 (click to download). At St Ursula's College, Yeppoon Queensland, HOD Science Barbara Pearson said that her students tried such variables as the type of food preferred (start with oats), time taken, complexity of maze, hazards such as light source, use of Vaseline on maze. Plenty of webpages with ideas.

ANIMALS OPTION

Note: very strict rules apply to the use of animals in schools in Queensland. Information can be found at the official link Animals in Education .

Effect of temperature on reproductive success of sea monkeys.

Moreton Bay College runs an open inquiry student experiment in Year 12 in which students have to investigate the effect of environmental conditions on the growth and development of an animal (or reproduction if non-vetebrates are concerned). In the one pictured below, this group is considering the effect of temperature on commercial sea monkeys (brine shrimp). Native ones have too long a life cycle to be any use in this experiment. If you want further information email their ever-helpful biology teacher Ms Josie O'Shea: [email protected]

Fruit Fly Inheritance

The fruit fly Drosophila melangaster is, and has been in the past, used for a variety of genetic experiments, including the study of genetic inheritance and to discover that genes were related to proteins. The fruit fly lifecycle is useful for students to study as it has a short lifecycle (11-15 days), is fairly easy to maintain and has a number of easily identifiable phenotypic features to study.

In this student experiment students are required to investigate the effect of an enviromental variable (such as light, temperature or pesticide resistance) on the growth and reproduction of the fruit fly Drosophila melanogaster . In the photos below, this group of Moreton Bay College girls is looking at the effect of alcohol. Fruit flies are bought from Southern Biological for $10 per tube and bred up by the lab staff. Each group need about 8 fruit flies per vial (4 males, 4 females) and about 9 vials (3 treatments x triplicate). A few years ago they tried alcohol on food but that was a disaster, then they tried alcohol on cotton balls (no good) and finally settled on alcohol on filter paper.

To analyse "inter-relationships" as per the criteria, it seems logical to try the experiment two ways: 1. control the alcohol concentration (eg 100%) and vary the frequency of exposure); or 2. keep the frequency constant and vary the concentration (30%, 70% 100%, or whatever). To count them, knock them out with carbon dioxide (acid + marble chips + delivery tube). Other variables that could be considered: temperature, type of food, amount of food, size of container on growth, reproduction of flies. One enterprising group even looked at the effect of cigarette smoke. Click here to download the student experiment task sheet as used by Moreton Bay College (my thanks to Josie O'Shea).

Environmental Toxicology: What are we doing to our frogs?

Glyphosate (N-(phosphonomethyl)glycine) is a broad-spectrum systemic herbicide used to kill weeds, especially annual broadleaf weeds and grasses known to compete with commercial crops grown around the globe. It is sold under the brand-names of Zero and Roundup . While glyphosate has been approved by regulatory bodies worldwide and is widely used, concerns about is effects on humans and the environment persist. [Graves, Lucia (24 June 2011). " Roundup : Birth Defects Caused By World's Top-Selling Weedkiller, Scientists Say". Huffington Post.]

Glyphosate is known to be toxic to fish and amphibians. A study published in 2010 proposed commercial glyphosate can cause neural defects and craniofacial malformations in African clawed frogs (Xenopus laevis). The experiments used frog embryos that were incubated with 1:5000 dilutions of a commercial glyphosate solution. The frog embryos suffered diminution of body size, alterations of brain morphology, reduction of the eyes, alterations of the branchial arches and otic placodes, alterations of the neural plate, and other abnormalities of the nervous system. A good biology student experiment may be to investigate the effect of increasing concentrations of glyphosate on tadpole metamorphosis. You will still need to consider ethical implications of your study and check the legislation on use of animals in experiments.

Mealworms eat polystyrene foam

Polystyrene foam (PS) has been used for decades as an insulating material in food containers (eg coffee cups) and as a cushioning material in packaging. It is generally considered to be durable and resistant to biodegradation. However, in September 2015, researchers from the School of Chemistry and Environment, Beihang University, Beijing, China and Stanford University, California, found that mealworms (the larvae of Tenebrio molitor Linnaeus) could chew and eat Styrofoam, a common PS product. The Styrofoam was efficiently degraded in the larval gut within a retention time of less than 24 hours. Within a 16-day test period, 48% of the ingested styrofoam carbon was converted into CO 2 , and the residue (about 49%) was excreted.

Further results indicated the essential role of gut bacteria in polystyrene biodegradation and mineralization, confirmed the presence of PS-degrading gut bacteria in the mealworms. See Environmental Science and Technology : 21 Sep 2015. Their method consisted of placing 500 mealworms in a polypropylene plastic container with a Styrofoam block of mass about 6 g. They used controlled conditions (25°C, 80% humidity, 16:8 (Light:Dark) photoperiod). The mass loss of the Styrofoam block as a function of time caused by mealworm consumption was measured periodically. A test of the survival of mealworms reared in the laboratory solely on a Styrofoam diet in comparison with those reared on the conventional diet of bran. See http://news.stanford.edu/news/2015/september/worms-digest-plastics-092915.html

Effect of global warming on pest species

The temperature of the earth is increasing due to global warming. Could this increase in temperature lead to increased reproduction rates of pest species?

Effect of global warming on marine species

One side effect of global warming is acid rain. If the pH of the Earth's waters or environment changes could this affect rates of reproduction or the survival of marine species?

Effect of protein on the growth of fruit flies

This is another one done by some students at Moreton Bay College. The manipulated variable is the quality of protein used as food for the flies. One type is semolina, the other is Nature's Way high protein food supplement - both of which contain which contains 18 different amino acids but in different proportions and absolute amounts. The photos below will give you an idea of what was done in this student experiment.

Effect of temperature on the growth and reproduction of the Common Egg butterfly

These butterflies can be bought from Ross Kendall at Butterfly Encounters ,17 Eldon St, Indooroopilly, Queensland Ph 07 3378 1187 or Mob 0402 254 370; Email: [email protected]. He's the guy at Indooroopilly (Brisbane) who keeps the caterpillars under his house and breeds them for weddings. See his webpage at www.butterflyencounters.com.au . I think he's with the Moth and Butterfly Association of Queensland .

Growth response of maggots to various conditions

Suggestion courtesy of Jonathan Grassby, Year 11 Co-ordinator, Craigslea State High School .

Growth rate of chickens eating different feeds

There are several factors that affect the chickens' growth rate and size at harvest. These include: breed, age at harvest, feeding regime, gender (males grow faster), and age of parent flock (ageing flocks produce bigger eggs and the chicks from larger eggs grow faster). Such factors may make a successful student experiment however the code of practice for animals in school scientific investigation lays down very strict requirements on such experiments ( see link above ). If you plan to do a chicken student experiment you should plan a year in advance.

An interesting investigation is done by some students at Moreton Bay College. They looked at the differences in growth rate depending on the type of food and feeding regime (as mentioned above). Regular and organic feeds were compared. It should be stressed that the conditions for being permitted to do such an experiment would not allow things like restricting food or water, or providing less than optimum conditions for the animals (correct temperature etc). The advice from Biology teacher Josie O'Shea ( [email protected] ) at MBC is to plan well ahead as the obstacles are great.

The photos below provide a stimulus for those considering an student experiment of this type. Some interesting background on feed requirements is provided by the Chicken Meat Federation of Australia.

Anaesthetising of barramundi

Clove oil has been used for a number of years to anaesthetize fish in seawater. In fish farming this is essential for performing basic procedures such as weighing, tagging, experimental work and for transport. It considerably reduces pathology risks from stress, injury and accident during handling. Clove oil is distilled from Euglena caryophyllata stems, buds and leaves and has been used on humans for centuries as a local anaesthetic. It is fast, relatively cost-effective and does not harm the fish.

Biology student Cristal Jones of Tully SHS conducted an student experiment to determine the optimum concentration of the Clove Oil Anaesthetic for juvenile barramundi. She speculated that Clove Oil, which is not well known or widely used, could become an alternative to the standard phenoxyethanol, quinalidine or benzocaine which are hazardous, expensive, hard to come by in developing countries and sometimes less effective. The relevance of determining the Optimum Clove Oil Anaesthetic concentration formula for juvenile barramundi extends into industrial and commercial situations, scientific studies, veterinary assessments and also in Aquaculture Facilities such as the Barramundi Ponds in the Tully State High School. Although it is preferable for the induction to be relatively fast with a quick recovery period, this is not always practical.

Cristal recently finished her PhD in the School of Biochemistry and Molecular Biology at the Australian National University and is now working in the biosecurity field. An article in the Weekend Australian (2 Oct 2010) about harvesting eggs from sturgeon to make caviar explains how sturgeon in Australia are anaesthetised harmlessly with clove oil when they are milked.

Click here to download a copy of Cristal Jones's 2003 student experiment . Note: her student experiment is provided as an example of the work being undertaken and is not meant to be an exemplar of an student experiment or of a particular achievement standard.

Barramundi experiments

As part of the Great Barrier Reef Marine Park Authority's Reef Guardian Schools program, Tully State High School has established reef related activities to promote the Great Barrier Reef and increase understanding and appreciation of the local marine environment. One of their programs is Aquaculture studies in which they aim to promote understanding of aquatic environments. There is a specialist aquaculture facility on the school grounds where students learn about the advantages, disadvantages and value of aquaculture in the north Queensland region. For Senior Biology students this facility enables them to do some imaginative student experiments on redclaw crayfish and barramundi.

Some of the Research Questions posed by students in their student experiments include:

1. effect of stocking density 2. light / dark effects on growth 3. feed types (pellets, pilchards, prawns, worms (and worm farm worms) 4. which fishing lure is most effective (hooks removed) 5. clove oil anaesthetic - as described above 6. temperature of water 7. water quality (pH, DO, nitrates, phosphates, etc) 8. frequency of feeding 9. clean tank walls as opposed to letting the algae grow on the walls of the tank 10. water depth 11. size of the tank 12. isolation v companionship

Soap tree sap as a mullet anaesthetic

Traditional owners of Minjerribah (Stradbroke Island, Australia) are said to have used crushed leaves from the indigenous soap tree ( alphitonia excels ) for catching fish. Quandamooka man, Matt Burns, who was born and raised at Dunwich on the eastern side of the island said that Minjerribah hunters used the crushed leaves as a fish poison. He said he was told by scientists visiting the Moreton Bay Research Station at Dunwich that the saponin in the leaf extract lowers the surface tension of the water, leading to deoxygenation which stuns the fish and causes them to float to the surface. He said that they would only be stunned for about a minute before they recovered, so they had to be picked up quickly and thrown on to the beach.

The problem seems to be that research so far has found that exposure to saponins initially causes hyperactivity but within 5 minutes all activity ceases and fish suddenly die. Scientists seem unable to find a dose level at which saponins act without causing death. This is unlike clove oil mentioned above. See the paper "Stunning fish" (Betäubung von Fischen) by Deborah Power and colleagues in Archiv Tierzucht (Archives Animal Breeding), Dummerstorf 51 (2008) Special Issue, 78-79 [http://www.archanimbreed.com/pdf/2008/at08si1p078.pdf Accessed 8 July 2016].

UQ's Moreton Bay Research Station at Dunwich would make an ideal place to study the anaesthetic properties of soap tree extract on barramundi or the local mullet but is probably not available to high school students. But you get the idea. Now, who can secure funding to test out the traditional hunting technique.

Redclaw Experiments

Freshwater crayfish native to tropical Queensland and the Northern Territory occur predominantly in the rivers flowing into the Gulf of Carpentaria and some easterly flowing rivers of northern Cape York Peninsular. Unlike other species of freshwater crayfish, the adult male Queensland Redclaw Cherax quadricarinatus has a distinct soft red patch on the outer margin of the claws, hence the name redclaw . Breeding activity is dependent upon water temperature and day length, and normally occurs between September and April within their natural range.

For school experiments protraction of the breeding period can easily be achieved by providing a controlled environment in which temperature is manipulated to simulate the onset of the breeding season. The Queensland Department of Primary Industries (DPI) - now the Department of Agriculture, Fisheries and Forestry (DAFF) - ran a number of redclaw aquaculture projects but these have since been disbanded due to funding cuts some years ago.

One of the scientists involved in the DPI project - Wendy Ensbey - is now a Biology teacher at Noosa District High School (Queensland). She said the starting point in a Redclaw student experiment was to read the DAFF brochure at www.daff.qld.gov.au/28_13348.htm . She has given some information (below) in response to questions from teachers:

Question 1. After breeding we have separated males and females adults into two tanks. There has been some cannibalism in both tanks. We are using cut-up pipes as hiding holes. We have read some information about using mesh but are not sure exactly how to use this. Are they mesh bags strung vertically from the surface or do we just put them out in the tanks as places to hide? If laying them out in the tank do they have to be bags or can they just be straight sheets that have been screwed up?

Answer 1. The bags provide a hiding place just like pond weed or other aquatic structures so the shape is less important than the amount of surface area and hence hiding spots. Crayfish just brawl with each other and attack if they can see each other. Two crayfish meeting may fight (either gender) or mate ( if male and female). Also, up to 10% may be hermaphrodite. I believe there was some inquiry into whether the hermaphrodite stage was a transition between sexes but the funding ran out.

Question 2. How much food should we feed the redclaw? We are using the small pellets. Should you supplement with other things? What do you do during the holidays with respect to food (They are in indoor tanks).

Answer 2. The warmer the weather, the more they should eat. To check how much they need, add cracked corn to your tank. It won't decay and pollute the water as quickly as the fish pellets and it is easy to see. When the crayfish clean up the corn you can feed them more pellets. The pellets are a higher percentage protein of course to maximise growth. Can't help with the concept of long term feed as our school farm (Noosa District SHS) has someone present through all holidays.

Question 3. We have been provided with conflicting information as to housing the redclaw. Should we have the girls in one tank and boys in the other or would a combination be better?

Answer 3.It is unimportant keeping the sexes separate because all individuals fight. There is no pecking order other than which one is bigger. Mating occurs if the female submits rather than fighting. Also you have hermaphrodite mystery to complicate things. Keeping the sizes separate is much more important as the big ones are much better at destroying the little ones. You need to monitor when your females are in berry and remove them as the babies will be a tasty snack for any near adult if they fall off their mum. Make sure the babies have lots of hiding areas - like bags.

Question 4 . Any specific advice for increasing the chances of survival for hatchlings?

Answer 4. Hatchlings first feed on plankton. An outside position of your tank or a sunny spot to encourage algae growth will help. Murky green is better than crystal clear. Just check your nitrate level stays low and the nitrite stays zero. pH at neutral to slightly alkaline is best.

Daphnia heart rate experiment

Some students have proposed that for their student experiment they will investigate the effect of a variable such as caffeine, glucose or Red Bull on their own heart rate or blood-glucose (or that of a fellow student). "Human subject" experiments for student experiments pose many problems, particularly safety concerns. In fact, many teachers and jurisdictions refuse to allow such human experimentation to occur and it would seem wise to check this out before you go too far (see caution in Homeostasis section below). There is also the problem of the validity and robustness of the data collection (particularly if it is subjective).

One solution to this is to carry out the experiments on insects. For example, you can use water fleas ( Daphnia magna ), a semi-transparent freshwater crustacean, to study the effects of caffeine on heart rate. You don't worry about having to learn how to take a crustacean's pulse: you can actually see the heart beating under a microscope. This idea came from Ms Sally Lockett - Biology teacher at Ormiston College, Queensland.

You could also try other chemicals: diphenhydramine (active ingredient in some over-the-counter decongestants such as Benadryl ), nicotine, and ethanol. Of course, you will have to negotiate safety issues with your teacher. Like any model system, Daphnia have advantages and disadvantages. On the plus side, they are fairly easy to keep, easy to study, and inexpensive. On the minus side, they are evolutionarily far-removed from humans, so you need to be cautious when interpreting your results. What happens when Daphnia are exposed to caffeine may or may not have similarities to what happens when humans drink coffee. A good webpage to get you started is: Sciencebuddies project ideas - Daphnia

Daphnia - salt concentration on size

Another popular experiment is to consider the effect of salt concentration on the size of Daphnia . This may be suitable for a unit on osmosis.

Beetles as pollinators

Some insects like bees usually collect pollen or nectar from only one species on a particular collecting trip, or even over a period of several days. Consequently, they are very good pollinators as they go from flower to flower of the same species. Other insects like beetles have the reputation of being less selective and of travelling to flowers of different species; they are thus less efficient as pollinators.

For an student experiment you could investigate just what range of flowers a particular beetle visits and consequently the range of pollen it carries. How are you going to keep a watch on the beetle as well as recording the plants it visits in sequence? How are you going to catch your beetle without showering it completely with the pollen of the flower it happens to be on? How will you clean your brush between beetles? What are the floral adaptations for beetle pollination and thus on which flowers are you most likely to find beetles? The abundance of flowering plants of a particular species might influence the animal's behaviour. How will you include this variable in your experiment? Click Project 4-14 for Prof. Jennifer McComb's resource sheet. Note: this student experiment does not involve manipulating variables; instead it relies on natural variation.

Collection of seeds by ants

It has been estimated that there are about 1500 species of Australian plants that are regularly dispersed by ants. The ants are attracted to the seed because it has a firm fleshy appendage (called an elaiosome ) and carry the seeds back to their nests. Only a little is known about this issue in Australia and could form the basis of an student experiment. Be aware that this type of investigation does not involve the manipulation of variables but relies on natural variation.

Ant-dispersed plants (dubbed myrmecochorous ) are woody shrubs in sclerophyll vegetation. Species in families Rhamnaceae , Fabaceae , Sterculiaceae are commonly ant dispersed as are members of the genera Acacia , Hibbertia, Goodenia. Look up these groups so you can recognize them in the bush. Many species shed their seeds in summer. How will you score your results if ants of several species appear on the scene unexpectedly and a brawl ensues? Are you going to study foraging only during the day or at night as well? Click Project 4-16 for Prof. Jennifer McComb's resource sheet.

Seed survival after ingestion

Not all of the seeds eaten by animals survive the passage through their alimentary canal; thus they end up in the animals' dung. An interesting student experiment would be to find out what proportion of seeds survives the alimentary canal and which seeds are distributed in dung. The experiment could relate seed size and structure with survival in animals with different types of digestive systems. You should select your seeds from those normally eaten by the animals e.g. oats, clover, medic, ryegrass, etc. and possibly include tomato which has a great reputation for survival. If the animals normally eat pellets you can make a mash of pellets and seeds and include these in the animal's food.

It would be interesting to include two animals with a contrasting alimentary canal e.g. hens and rats, sheep and horses. A large animal like a horse produces a vast amount of manure, all of which will have to be washed and sieved so use a small animal unless you are very keen! How are you going to compare live seeds in initial samples (before ingestion) with material which has passed through the animal? Click Project 4-17 for Prof. Jennifer McComb's resource sheet.

Effect of household detergents on freshwater organisms

Although many detergents are now what is called "biodegradable", degradation takes a finite time, and detergents which by one means or another find their way into rivers, lakes, swamps etc. could be quite harmful before they are degraded. In particular, detergents affect the permeability of biological membranes. You could investigate the tolerance of certain freshwater organisms to various concentrations of detergents. Organisms easily available in sufficient numbers for testing include mosquito larvae, small arthropods such as Daphnia, freshwater snails, fish, the plant Lemna , and tadpoles. As you will be killing animals you may find it less upsetting to knock off invertebrates rather than vertebrates.

It is important to remember are that it is very difficult to measure when a plant is "dead" compared to an animal, and that some animals like mosquito larvae go through developmental stages during the experiment. Click Project 13-1 for Prof. Jennifer McComb's resource sheet.

Gender Distribution and the Territorial Range of Turtle Weed Crabs on Heron Island

Monitor the population growth of organisms that rapidly reproduce asexually. It has been hypothesised that as the turtle weed crab inhabits a clump of turtle weed then the size of turtle weed will not influence the number of crabs inhabiting it because turtle weed crabs are known to only live in pairs therefore no matter what the size of the weed, there will only ever be 2 crabs inhabiting it.

The Effect of pH on the Strength of Keratin (hair protein).

Keratin is a protein that contains a high concentration of the amino acid cysteine; this contains a sulphur atom. The sulfur atoms from two cystines join together, forming a very strong disulfide bond (see below). These bonds are covalent and form strong links making the tertiary structure of the protein very stable. The disulfide bonds occur down the length of the keratin fibre and the cross-linking between the keratin chains account for the strength of hair.

Within each hair strand the keratin chains are also linked with hydrogen bonds between the oxygen atoms on the CO groups and the H atoms on either the OH or NH groups. Although they are individually weaker than disulfide bonds, hydrogen bonds are in much higher proportions to the disulphide bonds making them important in maintaining the tertiary structure of the protein. A good investigation would be to test the strength of hair as a function of pH. Try putting the hair in solutions of varying pH values from 1 to 14 (for say 10 minutes as an initial trial).

SOME OTHERS:

• Monitor the metamorphosis of brine shrimp from cyst to adult
• Gonadotrophic hormone injection of blackbream
• Compare the histology of animals from various classes, families etc and relate to adaptations
• Determine the tolerance limits of various organisms
• Influence of temperature on rainbowfish spawning
• Reproductive behaviour of aquarium fish
• Navigation of ants by pheromones (e.g. in trail-following)
• Effect of light and/or temperature on the behaviour of fish
• Direction-finding in pond snails. (In general snails are good animals to work on: they are easy to keep, move slowly and don't answer back!).
• Learning and colour/pattern recognition in relation to feeding behaviour of fishes.
• Energy budgets of insects of different ages

Correlational Studies

The following are experimental student experiment suggestions which do not involve the "artificial" manipulation of variables, rather relying on natural variation. This type of investigation is known as a "correlational study" as you you look for correlations between variables rather than artifically manipulating them.

• Feeding preferences of dogs/cats/green ants.
• Compare and display various egg types from a range of organisms and discuss the various adaptations, survival and developmental, the types of eggs convey.
• Determine the concentration of bacteria in various situations, e.g. milk at different ages, water from local creek.
• Isolate pure cultures of microbes from soil, the Banyan, the pond or any other safe source. Check your chosen source with your teacher.
• Compare the eggs of various fishes and relate the egg's properties to the niche of the egg and the adaptations it has for survival.
• Compare the histology of various structures of invertebrates using the microtome…… prepare slides of various structures for various adaptations.
• Compare the reproductive organs of various fishes….. possibly even various stages of maturity.
• Analysis of territorial behaviour in birds, e.g. magpies. (Ideal for keen bird-watchers.)
• Analysis of web-building by spiders as an example of innate behaviour.
• Stalking behaviour in cats. (In general many interesting projects can be carried out on pets but be sure to adopt a rigorous scientific approach using artificial manipulation of variables or correlation of naturally occurring variables (concomitant variation).
• How does the shell of a snail grow in size and shape as a snail becomes larger?

HOMEOSTASIS OPTIONS

Homeostasis is the condition where the body's internal environment remains relatively constant despite external fluctuations. It is the job of the body's organ systems to maintain it, even as they make necessary exchanges with the environment. Although many projects will be related to homeostasis in the human body, projects involving investigation of Stimulus-Response in invertebrates and in plants are also possible (see Behaviour Options below).

It may be worth reading the CAUTION below about using students as the subjects for experiments. There are several sensors that can be used to provide quantitative data. Diane Mackenzie at Clairvaux MacKillop focuses on homeostasis in Year 12 student experiments - using a number of sensors for measuring surface/skin temperature, ECG, heart rate, hand dynamometer for measuring force or strength, spirometer, respiration monitor belt. Students are taught to use LoggerPro software with some basic sensors in the Junior school.

How does human cognitive ability change with temperature change?

Humans can't think straight when they are cold. We all know that. But can this be quantified? If you gave a student some simple maths questions (15 + 8) and noted the score (out of 30) and then had the student climb into a wheelie bin of icy water for 5 minutes - would they be able to do as well on a similar test. I would think not. But, what process is operating here?

You'd need some good biological theory to justify your hypothesis before you even started. And are all students the same? Do students with a higher BMI respond with a smaller change in achievement (almost said "ability")? How do you measure a student's core temperature? Photos below courtesy of Moreton Bay Boys College.

How do energy drinks affect heart rate and BP?

Here's a extract from a newspaper "Energy drinks may help you to exercise but they also raise heart rates and blood pressure, say researchers. They contain chemicals including caffeine and taurine, an amino acid, that stoke up alertness but are potentially harmful to those with heart conditions. A study in Detroit has found they can even harm consumers who are simply sitting still. Dr James Kalus, of the Henry Ford Hospital, said: "We saw increases in both blood pressure and heart rate in healthy volunteers who were watching movies. They were just in a resting state."

This suggests a good student experiment. You could compare water, uncaffeinated soft drink, energy drinks (eg Red Bull) and make an assessment of the effect on psychomotor performance (reaction time, concentration, memory) and physical endurance (aerobic endurance - time when maintaining 65–75% max. heart rate) and anaerobic performance (maintaining max. speed) on an exercise bike.

Teachers are greatly concerned about using human subjects in experiments. After all, students are animals but are not the "live, non-human vertebrates" that the Animal Care and Protection Act 2001 or the 2004 Code of Practice refers to . Nevertheless, the concerns for student welfare are paramount. This is why teachers are very cautious when it comes to students doing experiments on themselves or on fellow students. Anyone planning to do experiments involving students as subjects should be aware of the risks and protocols and not take anything written here as condoning or promoting the practice. Each jurisdiction will have its own rules and precautions.

A note from one Queensland Biology teacher (below) may give an idea of the concerns he had.

Every year our Year 9 students conduct an student experiment into the effects of exercise on their body. They come up with a method which involves the type of exercise and the method for data collection. They make a choice to collect data on body temperature, heart rate, breathing rate, skin temperature, sweating rate (this is a little subjective). This is great for the homeostasis unit. I had a group of two students last year who tested energy drinks on their heart rate. Obviously this has some potential risks. To minimise these, I made them have a medical with their GP and then provide a medical certificate of this. They had to have a note from their parents approving the hypothesis, the method, and that they had read the outline of their introduction and the potential effects of the drinks on the body before they started. Also they could only have one energy drink in the day. (They assured me they have this every day anyway). They ended up splitting the drink into 5 parts and drinking these throughout the lesson while hooked up to the heart rate monitor. One of them also tested blood sugar. They were trained by their GP how to do this and had to demo their competence on how to test blood sugar to our school nurse before they could do it at school. We minimised risk by only one student being the one that tested so the equipment could not be mixed up and we had them dispose themselves too. I had discussed the idea with our SOO (Scientific Operations Officer, ie the "Labbie") who is trained in WHS and we came up with the above plan to minimise the risks. Our SOO was either present or on call to provide sterile swabs and gloves etc where required and the student sterilised the bench after completion with ethanol. From memory it was not overly successful as they did not allow enough time between 'drinks' for the drink to take and effect the blood sugar - though I think the heart rate was a little better…. They made the assumption that the drink would start effecting blood sugar immediately which it did not. I see risk assessments are to eliminate risk so far is reasonably practicable or to minimise risk so far as is reasonably practicable. The 'reasonably practicable' to me means we need to consider the need for students to learn also (in a safe environment), as that is what school are designed for. All of this that we did was way over the top I believe, but next time I would do the same…. I took the assumption that I could tell them not to do the topic for an student experiment, yet they may well do it at home. … If they did not do this at school where we can control the environment and manage the risks, they may well do them at home without consideration of risks… I know which one I would prefer. DT, 28 Nov 2012

ADDITIONAL COMMENT

Another Biology teacher said that "human subject" experimentation for an student experiment should be "actively discouraged". He said that the safety concerns were such that an student experiment should be ruled out anyway, but added:

"at no stage should we subject students in Senior Biology to any form of physiological testing of systems. Physical, by all means, as the data gathered can conceivably be thought of as representative. Data gathered physiologically cannot be accurate or robust enough over the course of a single term, with the necessary control of all variables, to deliver anything but superficial data."

How do caffeinated soft drinks affect heart rate and BP?

Here's a follow-up to the one above, but without using energy drinks such as Red Bull . Why not see how caffeinated drinks affect BP and heart rate. In this student experiment you might like to compare: water, uncaffeinated sugar-sweetened soft drink (eg uncaffeinated Coke), unsweetened caffeinated soft drink ( Diet Coke or Coke Zero . Perhaps you could look at psychomotor performance and physical endurance as above. See note above on concerns when students are the subject of experiments.

The Effects of Exercise on the Maintenance of Homeostasis

Does an individual's ability to return to their normal physiological state, after a period of exercise, depend on individual differences?

Homeostasis is the maintenance of a relatively stable internal environment. However, exercise disrupts homeostasis. The changes that occur in response to exercise are the body's attempt to reduce the stress that has been placed on the entire organism. Changes that are normal during exercise would be considered abnormal if they were occurring in a non-exercising individual. For example, the level to which the body temperature rises during exercise would be considered a fever if the person were not exercising. Exercise physiology is the study of both the functional changes that occur in response to a single bout of exercise and the adaptations that occur as a result of regular, repeated bouts of exercise. Suggested student experiment - courtesy of St Aidan's College, Corinda.

• Is reaction time altered following intense exercise? (need more than one type of exercise). How will reaction time be measured?
• Does reaction time differ according to the time of day?
• How initiating the respiratory system before exercise effects recovery. If athlete initiated respiratory system directly before commencing exercise then the athlete should have faster recovery rate because if muscle cells receive oxygen in advance, cells can aerobically respire during exercise, not anaerobically which forces lungs to respire heavily after exercise.
• The temperature of the earth is increasing due to global warming. Could an increase in temperature increase the body's food requirements?
• Exercising causes the core body temperature to increase. If diffusion rates increase in response to temperature, should food be consumed directly after exercise? What factors have the greatest impacts on reflexes and response time? What is the recipe for maximum response time? Teenagers are said to be most mentally active later in the day. Do reaction times during the day confirm this? Should school hours be altered? Are reaction times affected by food intake, rest, time of day or exercise? If so, should the school day be altered in some way to allow students to achieve maximum alertness.
• Hot Biceps. Why do my muscles get hot when I use them? How hot do weightlifters/cyclists muscles get? How long does it take for them to cool down?
• Muscle Fatigue. What causes muscle fatigue? How quickly do muscles recover ? How does training build strength?
• Cardiovascular fitness. Interval training versus weight training.
• Heart attack. What effect does exercise have on an ECG? What does the ECG of a heart attack victim look like?
• Breathe Deep. Yoga promotes well being and improves lung function - is it a good training technique? What other techniques are used?
• WII Fit . Can training improve reaction times - what other factors affect reaction times?
• Nerve pathways. Left brain, right brain dominant?
• Reflex Actions - Can individual differences be attributed to any physical differences.
• To dance or to run? Which sports increase your fitness faster over a set period of time? Not today!!! Does regular exercise have a greater influence on fitness than sporadic exercise? Should school students be required to exercise everyday?

BEHAVIOUR OPTIONS

Conditioning mice to follow a stimulus to food

This suggestion is about the factors affecting the ability of mice to run a maze? From a student (Jessica, Yr 12) at Moreton Bay College:

"The question that triggered the topic for this investigation was, "If humans are believed to have a greater learning ability at a younger age, and if they share a similar genetic makeup to mice, do mice learn at younger ages too?" The aim of the investigation was to determine how the factor of age in mice affects their ability to learn how to navigate a maze. It was hypothesized that the younger mice would demonstrate the greatest learning ability, the adults would have a slightly decreased ability and the teenagers having the smallest learning ability".

Here's a little bit of Jessica's introduction:

"Each different species of animal learn differently according to their anatomy, physiology and psychology that evolves from environmental pressures over many years. Several factors affect an animal's learning ability. These include developmental factors - such as age, physiological state and psychological state - and the sensory abilities, as well as the emotional state of the animal at the time of learning. "An animal's ability to learn greatly depends on its capacity to memorise. Mice, which have a remarkable genetic similarity to humans, refer to their episodic memory when learning how to navigate a maze. Episodic memory is the memory of events in our lives which, in the case of a mouse, would be the previous times they had run through the maze. The two learning types that exist for animals are able to be used by mice when navigating a maze: classical conditioning (learning by association) and operant conditioning (learning through a process of trial and error). "Classical conditioning is used in maze navigation in that the mouse associates reaching the end of the maze with a reward - usually food or its home. But it does not achieve the same effect that classical conditioning usually achieves, which is to produce a response from a conditioned stimulus (i.e. in Pavlov's dogs, the bell stimulus producing salivation response in the dogs to replace the food stimulus). "Operant conditioning is the major learning in action through the mouse having to trial different directional turns to see which combination leads it to the reward. As the mouse navigates the maze again and again, there are many physical changes that are occurring inside its brain that allow it to learn the correct route."

Sensation of smell and taste

It is often said that heavy smokers can't taste and smell things as well as non-smokers. Can you conduct experiments to show if this is so? Can you relate your findings to the length of time the people have been smoking and/or the number of cigarettes they have each day?

Easiest substances to use are ones that you can measure and dilute accurately so you can find out what is the lowest concentration of a substance your tester can smell or taste (a few suggestions - vinegar, honey, sesame seed oil, chilli sauce etc - don't use anything poisonous or substances that will evaporate very fast). Many of the things we think we taste, we really smell, and there are only four basic taste sensations, sweet, acid, salty and bitter. Click Project 12-1 for Prof. Jennifer McComb's resource sheet.

Schooling behaviour of fish

Many small fish show a tendency to school but it is not always clear whether they are responding to each other or to a common external factor. You can test some of the factors that influence schooling using an aquarium. Although this sort of work has mainly been done using freshwater "tropical" fish, it is equally feasible to use coldwater, estuarine or marine fish - as long as they are small enough. Click Project 9-2 for Prof. Jennifer McComb's resource sheet. If you plan to undertake an student experiment such as this you should be aware of legislation regarding the use of animals in education .

Landing sites of flies

Flies seem to land more thickly on some people's backs than others. Do they smell nicer (to the flies!) or is it maybe because they are wearing clothes of a certain colour? If the smell is attractive enough will the flies worry about colours? To standardize your experiment you will need some cooperative friends to have a swim then to sunbake and work up a nice sweat. To compare between people simply count numbers of flies in a marked area on their backs at set times. How will you make sure all the bits of cloth smell the same at the beginning of the experiment? Click Project 7-6 for Prof. Jennifer McComb's resource sheet.

• Relationships between green ants and other organisms
• Defensive behaviours of green ants
• Innate behaviour of insects to fly, walk etc
• Hearing of cockroaches
• Feeding behaviour of different species of fish
• Attack behaviour of fish to prey
• Different feeding patterns of fish feeding on different food types, still, moving etc
• Conditioning of barra to luring (fishing with lures)
• Conditioning barra to feed
• Conditioning mice to follow a stimulus to food….factors affecting ability to run a maze
• Conditioning chickens
• Chicken behaviour observations
• Conditioning sensitive weed and venus flytraps
• Effect of different coloured stimuli on barra feeding
• Design the most effective lure for catching barra
• Native Seed germination - heat or hormones - which is more effective?
• Behaviour of Woodlice - investigate turn alternation using a maze.
• Osmoregulation in crabs - set up a marine aquarium and investigate changes in salinity
• Cricket chirping - what affects the rate of chirping in crickets?
• Diurnal rhythms. What are they? Do they really exist in humans? Why? (Possible ERT stimulus).

ACKNOWLEDGEMENTS

Some of the student experiment ideas that follow have been suggested by the Senior Biology teachers at Tully SHS and Innisfail State College, Queensland, Australia. My thanks to Darrin Timms, HoD Land and Sea Science, Innisfail State College, 45 Flying Fish Point Road, Innisfail Qld 4860 Australia. I have been given access to the work of students at Moreton Bay College and would like to thank Biology teacher Josie O'Shea for her assistance. My thanks also to the Biology teachers from Nanango SHS and to Diane Mackenzie (Clairvaux MacKillop College), Sylvia Hicks (St Aidan's College), Shan Wainwright (Mt Maria College), Steve Mead (Browns Plains SHS), Charmaine Keal (Tullawong SHS) and John Andrews (HOD Science, Matthew Flinders Anglican College) for providing their student experiment tasks and suggestions.

I'd also like to thank Professor Jennifer McComb, School of Environmental and Life Sciences, Murdoch University, Western Australia for her encouragement and permission to use suggestions from her "Biology Projects for High School Students". Note: any of the tasks and comments on this page are not necessarily endorsed by the Queensland Curriculum and Assessment Authority or the schools mentioned. This work is about teachers sharing their own resources.

USE OF ANIMALS IN SCHOOL INVESTIGATIONS

Teachers should consult the Animal Care and Protection Act 2001, and The Australian code of practice for the care and use of animals for scientific purposes (2004) and be aware of the many laws and requirements governing the use of animals in schools, even for observation. You should be aware that you must submit applications to the Queensland Schools Animal Ethics Committee (QSAEC) and have those applications approved before any animal-use activities can be undertaken in your school. Non-State schools in Queensland must apply for Queensland Department of Primary Industries & Fisheries (QDPI&F) registration prior to sending an application.

Be prepared for a long wait if you haven't done this before: Moreton Bay College took 2 years to get approval for their mice and chicken behavioural experiments (see below). A good starting point for more information for Queensland teachers is the Animals in Education website. Click here for an extract from the Biology syllabus regarding animal experimentation. Different precautions are necessary when students themselves are the subjects of experimentation (eg in homeostasis experiments). There is a CAUTION in the homeostasis section later on about this.

Risk Assessment Teachers in non-government schools may find the Queensland Department of Education and Training's Curriculum Activity Risk Management Guidelines (CARA) useful.

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These biology experiments are designed for you to do at home or school using simple equipment. For some experiments, you may need a calculator. Here is a link to an excellent one provided by Web2.0calc .

To access experiments, click on one of the experiments listed below. In most cases, it is simplest to copy the experiment into a word processing program, and then print it out.

A Nervous Experiment

Do you think you need the same number of nerves in every part of your body? Where in your body might you need more nerves? See for yourself! Also in: Español

Air Pollution

The Phoenix metropolitan area, like many large cities, has problems with air pollution at certain times of the year. You can do a simple study to determine some of the factors that affect air pollution.

Farming ants might sound like a crazy thing to do unless you might like to eat chocolate covered ants. It turns out we can learn a lot from ants and the best way is to build your own ant farm. Also in: Español

Birds and Their Songs

We see them practically everywhere. They are found flying in the high mountains and soaring along the thermal winds in the low deserts. There are those that are reclusive and others you can watch from your own back yard. Also in: Español

Breaking Proteins

Catch and Sketch Plankton

Learn to focus on detail and make keen observations that could be overlooked in a picture in this lesson on scientific sketching.

Collecting Ants

There are several different ways to get ants for an ant farm, depending on when you would like to start the farm and how long you would like for your ant farm to last.

Microorganisms in action! Turn a pile of grass clippings into an experiment.

Cutting Out Brain Tumors

Try out some of the new techniques that neurosurgeons are using to guide them during surgery.

Dr. Biology's Virtual Pocket Seed Experiment

Dr. Biology has been busy working on a new experiment and he needs your help. He has collected so much information from the experiment that he needs someone to analyze the data. All the results have been recorded in photographs, including some cool animations. Also in: Español | Français

Be Part of Ask A Biologist

By volunteering, or simply sending us feedback on the site. Scientists, teachers, writers, illustrators, and translators are all important to the program. If you are interested in helping with the website we have a Volunteers page to get the process started.

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Top 10 Biology Experiments You Don't Want to Miss

January 14, 2019 4 min read biology experiments science activities

A few years back we shared a series about how to teach the different areas of science at home, which you can find here:

• Teaching Biology at Home
• Teaching Earth Science at Home
• Teaching Astronomy at Home
• Teaching Chemistry at Home
• Teaching Physics at Home

The posts in the series have remained some of our most popular posts and so we thought we would help you all out by sharing our favorite experiments for each discipline!

We are going to start this series out with biology - here's how you can teach biology at home .

And without further ado, here are our top 10 biology experiments!

Top 10 Biology Experiments

1. Dissect a Flower  

Many of the typical spring blooms, such as lilies, tulips, and daffodils, have clearly seen elements, which makes them excellent specimens for your students to study the structure of a flower.

One of the best ways to do this is through a flower dissection! These step-by-step directions for a flower dissection will help you examine the structure of a flower.

2. Raise a Butterfly

Butterflies go through an amazing life-cycle. A butterfly lays an egg, from which a caterpillar emerges. Then, the caterpillar eats and grows, eventually forming a chrysalis. And several weeks later a butterfly emerges!

There is nothing like watching this process in action! And these instructions on how to grow a butterfly will help you observe this life cycle in action.

3. Extract DNA 

DNA is the stuff that tells our cells what to do and how to look. It resides in the nucleus of a cell, so as you can imagine it is quite tiny. In fact, you normally need a very powerful microscope to see DNA for yourself.

That is unless you extract it and force it to join up together into one giant mass of DNA. And that is exactly what you do with this Banana DNA Extraction experiment .

4. Make a Seed Board 

Plants start their lives out as seeds and there is a huge variety of seeds, just like there is a huge variety of plants.  

These four steps for making a seed board will help your students appreciate the differences and similarities between seeds.

5. Dissect an Owl Pellet 

This one often grosses people out, but dissecting an owl pellet is a great way to learn about bones and animal diet.

Don't worry, owl pellets are not from the backside of an owl. Owls swallow their prey whole, so a few hours after the meal, they will regurgitate the indigestible parts in the form of a pellet.

These four steps for dissecting an owl pellet will help you get the most of this fascinating but slightly suspect dissection.

6. Look at Fingerprints

Our body is covered with an amazing organ know as skin. It's the largest organ of the integumentary system. The  skin on our fingers, toes, palms of your hands, and soles of your feet is folded into tiny ridges. These ridges form swirling patterns, that help our hands and feet grip things.

These directions for examining your fingerprints will help your students understand just how amazing our skin is!

7. Grow an Herb Cutting

Roots are the structure of a plant that anchors into the ground and helps the provide the plant with the nutrients it needs to grow.

These directions for growing an herb cutting will help your students see how roots grow and get a chance to examine roots up close without getting dirty! 

8. Make a Habitat Diorama 

Our planet is covered with different types of habitats. Habitats are the place that is normal for the life and growth of a certain animal or a plant. In other words, it's the area where an animal or plant resides.

These directions for how to make a habitat diorama will help your students learn about the different plants and animals in an area in a hands-on way.

9. Eat a Cell Model

The cell is the basic unit of life, but it's so small that we can't see the cell's structure with our naked eyes. Enter the cell model.

You can make a jello cell, a cake cell, or a cell calzone to eat, but whatever cell you choose to snack on, these edible models will help your students visualize this basic building block of life.

10. Create a Fall Leaf  (or Signs of Spring)  Journal

When you study biology, it's a good idea to learn about the nature surrounding you. A  Fall Leaf journal  or a Signs of Spring journal will help your students learn about the trees and bushes that are in your area.

Wrapping it Up

There are loads more options for biology experiments out there that we love - in fact, we probably could have done a post with 100 experiments! But these are the ten we don't want you to miss.  If you want more biology experiments, check out our Biology Pinterest board .

If you want it all pulled together for you, check out the following our homeschool science programs with easy-to-use plans for teaching biology:

• For Preschool – Intro to Science  and  Summer's Lab
• For Elementary Students –  Biology for the Grammar Stage ,   Biology Lapbooks , The Sassafras Science Adventures ( Zoology ,   Anatomy , and   Botany )
• For Middle School Students –   Biology for the Logic Stage
• High School Students –   Biology for High School

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Fun and Interesting Biology Experiments for High School: Examples

A high school biology class is more hands-on than middle school science. All biology courses include experiments, whether they are part of a controlled laboratory class, a science fair, or individual student projects. 

Get ideas for simple and easy biology experiments you can incorporate into your classroom by exploring some fascinating high school biology experiments.

Table of Contents

Examples of Biology Experiments for High School

A wide range of biology projects for teens are available, whether you are looking for a science fair project or a class assignment.

Frog Dissection

It is a quintessential part of high school biology to dissect a frog. For your class, try to obtain both female and male specimens so that students can see the eggs and compare the insides.

Flower Dissection

Frog dissection can make high schoolers uncomfortable. Instead, dissect a flower. The teens can identify the male and female parts of the flower. Using a microscope to examine flower intricacies can be fun for high school students.

Diversity Among Plant Samples

To observe diversity among plant samples in a natural setting, such as a local park, is another simple biology experiment. In order to make the experiment more detailed, students can rub collected samples on filter paper to see which plants have which colors. 

Plants exhibit different colors for a variety of reasons, which teens can investigate.

Phototropism

Educating children about how phototropism affects plants can be enlightening. Different materials can be used to affect light in an experiment. It is possible to see how changing the light affects the plant’s growth.

Water From Common Sources

There is always water around. Unfortunately, water contains a number of elements as well. Collecting water samples from different sources and viewing them under a microscope is a great experiment. 

After comparing their results, students can postulate why a given source of water would harbor more organisms than another.

Yeast Experiment

In another experiment, molds are monitored over a two-week period on a piece of bread.

Taste Perception

There is a taste for everything for everyone. Quite literally! There are some people who like sour things and there are others who like sweet things. Do an in-class experiment to find out if everyone perceives taste the same way and has the same threshold for taste.

Disinfectant Effectiveness

Have you ever wondered how effective hand sanitizer is at killing bacteria? Put it to the test! Bacteria can be grown in a Petri dish with paper soaked in peroxide, white vinegar, rubbing alcohol, etc. Discover how each one inhibits bacteria growth.

Pea Plant Genetics

Students can recreate Mendel’s genetic experiments on pea plants. Students can determine the genotype of each parent plant by growing pea plants and comparing their phenotypes.

Examining Fingerprints

A fingerprint is one of the most amazing features of the human body. In addition to being able to open your phone with them, each one is unique as well. Examine the different aspects of your fingerprint by putting it on paper. Everyone in the class should compare their fingerprints.

Comparing Animal and Plant Cells

A student can compare the cells from their cheeks to those from an onion to gain a deeper understanding of animal and plant cells. The cell structures can be better seen under a microscope by staining the cells with iodine or another dye.

An effective way to help students understand DNA structure and function is to create a DNA model. You can build a fairly realistic model of the double helix using candy, string, and toothpicks.

Water Bottle Germs

High school is a time when many people refill their water bottles. Is the bottle contaminated with germs or bacteria? Can a disposable water bottle be refilled safely? Take swabs from the water bottles your students use and look for bacteria around the lid or on the bottle.

Testing Hair

Hair products are widely used by teens. Are they really effective? Take a few hair samples from teens in your class. Check out what happens to the hair when you add common hair products.

Water Cycle

It’s not difficult to understand the water cycle. Teenagers can examine the water cycle firsthand by creating a water cycle experiment. Put a baggie filled with water on a window and have them tape it to it. During the demonstration, they will observe evaporation, condensation, and precipitation.

Closed Ecosystem Bottle

The idea of something having its own ecosystem can be difficult for students to comprehend. It is possible, however, to create a closed ecosystem using a plastic bottle.

Field Survey Biology Experiment

The best part about this experiment is that it is easy, cheap, and you can conduct it in a variety of places around your school or send it home with your students. Monitoring the samples that you collect over time and observing the surrounding area is the objective.

Materials You’ll Need

You will need the following items for this experiment:

• Samples should be collected in a jar or baggie
• Using tweezers
• Hand gloves
• Marking an area with stakes and string or cones is helpful
• To take notes, use paper or a journal
• Microscope, slides, and slide covers

Observation Instructions

It is important to choose an area where you can re-mark easily or where you can leave the markings up so you can return to the same designated area over several months.

• Students should choose one spot to observe. It should not be larger than two to three feet square.
• Is there evidence of animals around? (Search for prints, scat or guano, fur, owl pellets, etc.)
• Can you tell me what kind of plant life you see? Plants (such as moss, lichen, and weeds) should be observed.
• Is there a fungus on your hands? If you see mushrooms or other fungal growth, look for them.
• What kind of insects do you see? Encourage students to look specifically for relationships here, such as mosquitoes and water or bees and flowers.

Sampling and Classroom Instructions

Follow these instructions to bring research back into the classroom.

• Encourage students to make connections and note relationships in their marked areas. They should make an inventory of the area and draw a crude map showing where everything is located.
• Take samples of soil, fungus, moss, plant life, insects, etc., using tweezers if possible.
• Water or soil pH value
• Water microorganisms
• Observing plant cells under a microscope
• Flowers that you find and their comparative structure
• Journals or interactive notebooks should be required for students to record everything.

In the classroom, set up stations for viewing, dissecting, drawing, and testing pH. Having this choice will allow students to examine their specimens in their own way.

Testing for Bacteria

Students should find out where the most bacteria are hiding. For those looking for a lab that guarantees results, this experiment is perfect. Bacteria are always lurking somewhere in students’ Petri dishes, waiting to grow.

Materials you will need are listed below.

• Three Petri dishes per student were prepared
• Swab samples that are sterile
• The painter’s tape
• Tape from Scotch
• Marker with permanent ink
• Paper with graphs
• Hand scissor

You can also purchase sterile Petri dishes and agar separately; however, it is more likely that students will contaminate the plate before swabbing.

Preparing Your Petri Dishes

The preparation of your Petri dishes is crucial to the success of your experiment.

• Students should identify three places (but within the same physical location, such as home or school) where they will swab for bacteria before opening any materials. Have them hypothesize about where bacteria are most likely to grow.
• Cut out three circles from the graph paper after tracing them on the Petri dish.
• Make a line that indicates the circle’s ‘top’ in pencil. Regardless of where you draw the line, you will need something to indicate how your Petri dish is oriented if you want to be sure you’re tracking the same colony every time.
• On the back of the graph paper circle, write the location and date where you will take the swabs. All three Petri dishes should be treated the same way.

Collecting Samples

Students should bring their closed Petri dishes and unopened sterile swabs to the site. They should carefully:

• Prepare a flat surface for the Petri dish.
• The swab should be unwrapped.
• The swab should be swiped across the area suspected of having bacteria.
• Carefully close the lid after wiping the used swab across the agar with the used swab.

If you want to prevent the Petri dish lid from accidentally falling off, you can tape it shut.

Evaluating Results

After swabbing the areas, the results are what matter.

• Students should draw circles the size of Petri dishes in their lab books or on separate graph paper. For each dish the student has, draw one week’s worth of Petri dishes.
• Draw the size of the colonies in their notebooks as they grow, making daily observations. Over a month, have them observe on the same day(s) if they cannot observe daily.
• Additionally, they should record the color and other characteristics of their bacteria colonies.
• A conclusion should be written by the students at the end of their study.

The Effect of Light on Growth

The purpose of this lab is to investigate how light affects plant growth. Almost any plant can be used, but cress will grow more quickly, so your students will get results faster.

Make sure you have all the materials you need.

• Cup or bowl made of Styrofoam
• Soil for potting
• Taking pictures

Instructions

Now that you have your materials ready, it’s time to get started.

• The seeds should be planted in the cups on Day 1.
• The cups should be labeled according to the type of light you will use. There are several types of light that you can compare, such as sunlight versus complete darkness.
• Every day after the initial day, take a picture of each cup and try to measure its growth.
• Note the color and shape characteristics of the sprouts for your lab entries.

Planaria Regeneration

Students will test whether cutting planaria makes a difference in how they regenerate and observe how quickly they regenerate.

You will need to grab something in order to conduct this experiment.

• There are nine planarias
• Three small plastic Petri dishes
• Petri dish, large, made of plastic
• Pipette made of plastic
• Magnifying glass 1
• Coverlip made of plastic
• Water from springs
• Disposable paper towels
• Pack of ice (optional)

Setup Instructions

When it comes to creating fun and interesting biology experiments for high schoolers, getting the setup right is half the battle.

• To avoid confusion later, number the three small Petri dishes.
• Move a planarian into the large Petri dish using the pipet.
• Try setting the Petri dish on an ice pack for a few minutes at this point. There is no need to do this, but it will slow down the planarian, making it easier to cut.
• In the back of the head
• The middle of the road
• To the right, towards the tail
• Each segment should be transferred gently to a new Petri dish (with spring water) using the pipet.
• All remaining worm segments should be repeated in the same manner.
• Keep an eye on the planaria every day. Upon appearing on the planarian’s head, the photoreceptors (black dots that resemble eyes) will indicate that the regeneration is complete.

Scientific Method and High School Biology Experiments

Students are taught science elements in high school biology. These main focuses include the scientific method. Participants in science are encouraged to think like investigators and to generate hypotheses about what will happen in a given experiment. The experiment is then designed to either prove or disprove the hypothesis. By doing so, teens are encouraged to engage in the scientific method while learning other scientific skills, such as:

• Using present factors and knowledge to make a rational estimate
• Ability to pay close attention to details and monitor
• What to do if you turn out to be wrong and how to move on
• Skills in quick thinking

Biological experiments can be fun, but there is also an educational component to them.

Fun and Interesting High School Biology Experiments

Taking biology in high school can be a lot of fun for teens. It is possible to make biology more than just another course of study by finding the right experiment. You never know, right? You might even inspire your student to enter a science fair or to pursue a science-related career?

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Practical Biology

A collection of experiments that demonstrate biological concepts and processes.

Observing earthworm locomotion

• Practical Work for Learning

Published experiments

This website is for teachers of biology in schools and colleges. It is a collection of experiments that demonstrate a wide range of biological concepts and processes.

Experiments are placed within real-life contexts, and have links to carefully selected further reading. Each experiment also includes information and guidance for technicians.

Why use practical work in Biology?

Biology is a practical science. Practical activities are not just motivational and fun: they also enable students to apply and extend their knowledge and understanding of biology in novel investigative situations, which can aid learning and memory, and stimulate interest.

We have published a new set of resources to support the teaching of practical science for Key Stages 3-5. The resources are part of the Practical Work for Learning project , which explores how three different teaching and learning approaches can be applied to practical work. Visit the Practical Work for Learning website to find out more.

Help and support in using the experiments

Unfortunately, we are unable to respond to questions from teachers, technicians or students on how to use the experiments on this website.

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Hands-on Activities for Teaching Biology to High School and Middle School Students

• Hands-on Biology Activities

• biological molecules
• cell structure and function
• cellular respiration and photosynthesis
• cell division and genetics
• molecular biology
• evolution and ecology
• human physiology .

The expression "hands-on, minds-on" summarizes the philosophy we have incorporated in these activities - namely, that students will learn best if they are actively engaged and if their activities are closely linked to understanding important biological concepts. 

Most of our activities support the  Next Generation Science Standards (NGSS). 

Additional resources for teaching biology are available at Minds-on Activities for Teaching Biology .  These teaching resources include remote ready analysis and discussion activities , games, and overviews of important biological topics, including major concepts, common misconceptions, and suggested learning activities. We encourage you to  subscribe to our listserv  to receive notices when we  post new activities or significantly improved versions  of current activities.

We invite general comments in this comments section. If you have comments on specific activities, please use the links above to get to the comments section for each activity.  We welcome suggestions for other teachers, including useful preparatory or follow-up activities, additional resources, any questions you have, or a brief description of any problem you might have encountered.

If you would prefer to send your comments or questions in a private message, please write Ingrid Waldron at [email protected] .

As a first year IB Biology teacher in Australia, I am very grateful for all of Ingrid's hands-on, minds-on activities. I love how they link to real-world scenarios, add meaning and foster critical thinking. Thank you so much!

I am a public high school science teacher, and I've used many of your materials. When I need something new, I often go to your site first because you have such high-quality, hands-on, minds-on, NGSS-aligned activities.

Thank you for creating these resources and for making them free. These resources are needed and much appreciated!

I've been a big fan of your Serendip Studio resources for years! I've used many of your activities in my Biology and my AP Biology classes. Your site is always one of the top 3 that I mention to other Biology teachers when they ask for recommendations of great websites. Thank you so much for your dedication to Biology education.

I am a high school Biology teacher and have been for ten years. I just wanted to thank you for making your amazing materials so accessible. It is very rare to find activities that are so accurate and comprehensive. I rarely need to modify the activities but it is helpful to be able to given the word document format. Thank you! Thank you! Thank you!

I am training to be science teacher and will graduate next year (2015) and I find very helpful in retrieving your lab practicals. I have retrieved many and hope it will help me much in my teaching career. Thank you very much you producing this practicals.

Science and PBL

Hi! I am the Chair of Science of an alternative learning school that focuses on Project Based Learning Curriculum. This is by far and away the best website that I have ever seen, in all of my years of teaching, for Science PBL Tasks. Thank you very much for your assistance. And please notify me of updates.

Biology. AP Biology, Forensic, Anatomy

I teach four HS sciences and found your activities to be a wonderful addition to my curriculum in all four areas! They provide excellent reinforcement and depth to the content we are studying. Your activities truly help the students learn and have saved me a lot of time in preparation. I highly recommend these activities. THANK YOU and well done.

This is my first year teaching Biology, and as I work to incorporate more meaningful labs into my curriculum, your site has been so very valuable! I especially appreciate how your labs include the scientific method so thoroughly and allow for student design of experiments! Also thank you for providing the word documents to allow teachers like me to edit the labs to fit our specific groups of students! Keep up the good work!

I am a Community College instructor on the prowl for activities and resources to incorporate into our Intro Biology lab. I have found wonderful stuff here and have used the Sockosome Meiosis activity with great success.

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Ricardo Azpiroz, PhD Richland College Dallas, TX

Using our material in an online lab manual

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Download minds-on activities for teaching biology.

Introduction and Activities Listing

Intro and Biological Molecules

• Characteristics of Life
• Levels of Organization in Biology  (NGSS)
• Introduction to Proteins and DNA  (NGSS)
• Enzymes Help Us Digest Food (NGSS; hands-on)
• A Scientific Investigation – What types of food contain starch and protein? (NGSS; hands-on)
• Coronaviruses – Introduction (NGSS)
• Who Took Jerell’s iPod? -- An Organic Compound Mystery (hands-on)
• Is Yeast Alive? (hands-on)
• Macromolecules Jeopardy

Cell Structure and Function

• Cell Structure and Function – Major Concepts and Learning Activities
• Cells – How do they carry out the activities of life? (NGSS)
• Why do some plants grow in odd shapes? (NGSS)
• Introduction to Osmosis (NGSS; hands-on)
• Cell Membrane Structure and Function (NGSS; hands-on)
• Cell Vocabulary Review Game

Cellular Respiration and Photosynthesis

• Cellular Respiration and Photosynthesis - Key Concepts and Activities
• How do organisms use energy?  (NGSS)
• Using Models to Understand Cellular Respiration (NGSS)
• Using Models to Understand Photosynthesis  (NGSS)
• Photosynthesis, Cellular Respiration and Plant Growth (NGSS; hands-on)
• Food, Physical Activity, and Body Weight  (NGSS)
• How do muscles get the energy they need for athletic activity?  (NGSS)
• Alcoholic Fermentation in Yeast – A Bioengineering Design Challenge  (NGSS; hands-on)
• Photosynthesis and Cellular Respiration  (NGSS)
• Where does a tree’s mass come from?  (NGSS)
• Photosynthesis Investigation  (NGSS; hands-on)

Cell Division

• Mitosis and the Cell Cycle (NGSS; hands-on)
• Mitosis and the Cell Cycle (NGSS)
• Meiosis and Fertilization – Understanding How Genes Are Inherited (NGSS; hands-on)
• Understanding How Genes are Inherited via Meiosis and Fertilization (NGSS)
• Comparing Mitosis and Meiosis
• What causes melanoma and other types of cancer? (NGSS)
• Mistakes in Meiosis – Down Syndrome or Embryo Death (NGSS)
• Mitosis, Meiosis and Fertilization Vocabulary Review Game
• Genetics Concepts and Activities (NGSS)
• Genetics (NGSS; hands-on)
• Genetics Intro – Family Members (NGSS)
• Genetics Sickle Cell Anemia and Trait (NGSS)
• Genetics Probability – Sex Ratios (NGSS)
• Mistake in copying DNA & Dwarfism (NGSS)
• Soap Opera Genetics (NGSS)
• Were the babies switched? The Genetics of Blood Types (NGSS; hands-on)
• Dragon Genetics I (hands-on)
• Dragon Genetics II (hands-on)
• Learning about Genetic Disorders
• Genetics Vocabulary Review Game
• Genetics Jeopardy

Molecular Biology

• Molecular Biology: Major Concepts and Learning Activities (NGSS)
• DNA (NGSS; hands-on)
• DNA Function, Structure and Replication (NGSS)
• How Genes Can Cause Disease - Introduction to Transcription and Translation (NGSS; hands-on)
• How Genes Can Cause Disease - Understanding Transcription and Translation (NGSS)
• UV, Mutations and DNA Repair (NGSS; hands-on)
• What types of mutations cause more vs. less severe muscular dystrophy? (NGSS)
• Making Red Blood Cells (NGSS)
• Genetic Engineering Challenge – Preventing Vitamin A Deficiency (NGSS)
• Gene Editing with CRISPR-Cas – Potential Sickle Cell Anemia Cure (NGSS)
• Molecular Biology Vocabulary Review Game
• Resources for Teaching and Learning about Evolution
• Evolution by Natural Selection (NGSS; hands-on)
• What is natural selection? (NGSS)
• Natural Selection and the Peppered Moth (NGSS)
• How have mutations and natural selection affected fur color in mice?  (NGSS)
• How Whales Evolved (NGSS)
• How Eyes Evolved – Analyzing the Evidence (NGSS)
• How does evolution result in similarities and differences? (NGSS; hands-on)
• What is a species? (NGSS)
• Coronavirus Evolution and the COVID-19 Pandemic (NGSS)
• Evolution and Adaptations (NGSS)
• Ecology Concepts and Learning Activities (NGSS)
• Exponential and Logistic Population Growth Models vs. Complex Reality (NGSS)
• Some Similarities between the Spread of Infectious Disease and Population Growth  (NGSS; hands-on)
• Stability and Change in Biological Communities (NGSS)
• Food Webs, Energy Flow, Carbon Cycle and Trophic Pyramids (NGSS)
• Food Webs (NGSS)
• Carbon Cycles and Energy Flow through Ecosystems (NGSS)
• Trophic Pyramids (NGSS)
• Introduction to Global Warming (NGSS)
• Food and Climate Change – How can we feed a growing world population without increasing global warming? (NGSS)
• Coral Bleaching (NGSS)
• Global Warming (NGSS) (NGSS)
• Resources for Teaching about Climate Change
• The Ecology of Lyme Disease (NGSS)

Human Physiology and Health

• Negative Feedback, Homeostasis, and Positive Feedback – Examples and Concepts  (NGSS; hands-on)
• Homeostasis, Negative Feedback, and Positive Feedback  (NGSS)
• How do food molecules reach our muscles? (NGSS)
• How do we Sense the Flavors of Food?  (NGSS; hands-on)
• COVID-19 Vaccines (NGSS)
• Molecular and Evolutionary Biology of HIV/AIDS and Treatment (NGSS)
• Resources for Teaching Cancer Biology
• Carbohydrate Consumption, Athletics, Health – Using Science Process Skills
• Vitamins and Health – Why Experts Disagree
• Regulation of Human Heart Rate (hands-on)
• Should You Drink Sports Drinks?  When?  Why?

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Remote Ready Biology Learning Activities

Remote Ready Biology Learning Activities  has 50 remote-ready activities, which work for either your classroom or remote teaching.

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• Minds-on Activities for Teaching Biology 1 week 1 day ago
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• Food, Physical Activity, and Body Weight 2 weeks 2 days ago
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• Teaching resources

Experiments that complement VCE Biology Units 1 and 2

The following are practicals developed and compiled by GTAC to complement the 2016 - 2021 VCE Biology curriculum. Some practicals are designed to run with additional educational resources and links to these resource are provided.

Algae immobilised in alginate balls - Studies of photosynthesis and respiration

A practical to test the conditions in which algae conduct photosynthesis and respiration. Click here to view this practical .

Preparing a bacterial stain for microscopy

A practical which involves fixing bacteria to a glass slide and then staining them to view under a microscope. Click here to view this practical .

Calibrating a compound light microscope

A procedure that describes how to calibrate your microscopy to estimate cell size. Click here to view this practical .

Energising cells - Investigating autotrophs and heterotrophs

An practical to investigate how some unicellular organisms obtain their energy. Click here to view this practical . This practical also has complementary educational resources for classrooms. Click here to view these additional resources .

Glucose solutions for diabetes simulation activity

A series of simulations where students diagnose whether patients have normal or disordered blood glucose regulation. Click here to view this practical . Click here to view additional resources.

Prepare a leaf epidermal peel

A practical involving the preparation of a peel of a leaf epidermis for microscopic observation of the epidermal cells, guard cells and leaf hairs if present. Click here to view this practical .

Microbiology methods for bioprospecting

A practical that involves the use of a disc diffusion method to test the potential of antimicrobial agents extracted from plants. Click here to view this practical .

Mitosis in growing root tips

A procedure that stains chromosomes in the growing root tips of garlic in order for viewing under a light microscope. Click here to view the resources for this practical .

Osmosis under the microscope

A practical involving the observation of osmosis in red onion epidermal cells. Click here to view this practical .

Stain dicot and monocot stem sections

A practical involving the staining of dicotyledons or monocotyledons sections so as to identify each through their arrangement of vascular bundles. Click here to view this practical .

Measuring stomatal density - Leaf impression method

A method for the preparation of a leaf surface impression or cast, allowing for identification and quantitation of stomata. Click here to view this practical .

Yeast immobilised in alginate balls - Studies of respiration

A method to immobilise yeast in alginate balls so as to detect respiration via pH change. Click here to view this practical .

Website by Lucy Martin, David Faure & Richard Scarr

Updated 29 August 2024

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• 12 Investigation ideas with a biological twist.
• The Investigation

Spring, summer or autumn germination of seeds? Does light affect seeds differently according to their normal season of germination?

The effect of abiotic factors on the germination of seeds is a bit of a standard lab, the methods are very easy and doesn't show much personal engagement unless students can put an interesting spin on the investigation. This idea is one way to do just that.  Research is necessary on the choice of seeds for the experiment. Students find out about the normal germination time of the seeds, the method the seeds use to control this germination time and then test testing the specific effect of light on germination. The colour of light (red / far-red, etc.), the intensity of light, or the day/night length could all be interesting factors, as could other abiotic factors appropriate to the season.  Biodynamics agricultural ideas could be a rich source of possible hypotheses to test too.

Investigation of a method of scarification on the germination of seeds.

Scarification involves weakening, opening, or otherwise altering the coat of a seed to encourage germination. Scarification is often done mechanically, thermally, or chemically.  Some mechanical methods involve nicking, sanding, or clipping off part of the seed's shell so water can get to the inside part to activate germination. Chemical methods can use sulfuric acid, hydrogen peroxide or alcohol. Thermal scarification is covered in detail in the next idea. You can search YouTube to see a selection of videos on this topic.

The effect of freezing or winter cold on germination of perennial seeds.

Some seeds (perennials) require a period of moist cold before they germinate. They get this naturally in the wild over winter but plants relying on natural cold stratification usually make many seeds, because the process in nature results in the death of many seeds. Gardeners have developed ways of creating these conditions to promote germination more safely, called cold moist stratification. Any of the following methods would make interesting investigations: How long should this freezing treatment last?  What minimum temperature is required to have the 'freezing effect'?

Cold water soaking: Put seeds into a jar in the fridge and change the water frequently. This is supposed to be like snowmelt,  it is supposed to wash away germination inhibitors from the seeds.

Refrigeration : Mix seeds into a little clean sand, sterile soil or paper towels. Put this into a resealable plastic bag in the fridge.  Three months is a good time, but sometimes you can get away with less, even 3 weeks.

Autumn / fall planting: Plant the seeds in pots before it gets too cold and cover the pot with something which will allow a little water to get in but not too much and also insulate them from extremes of cold.

• Winter solstice sowing: (December 21 in northern hemisphere) Planting in the middle of winter or even later, up to February. The harder your winter the later you can plant. This takes advantage of the natural swings between cold and warm that occur in late winter. Europeans have been winter sowing for decades--I've seen a mosaic from Roman times depicting Frenchmen winter sowing beans.
• Outdoor treatment : "Plant" seeds as in the refrigeration method, but instead of putting the ziplock bags in the fridge, put them outside in a shed during winter. This gives the seeds a fluctuation in temperatures instead of steady cold of the fridge. Keep the seeds away from direct light (and hungry mice!).

Any of these would be an improvement on the all too common 'factors which affect germination' experiments.  Deliberately investigating a specific biological mechanism is better than simply describing an observed effect, without an understanding of why this happens.

This book, Norman Deno "Seed Germination Theory and Practice" (1993) is well known by gardeners in the USA. It describes many reasons and mechanisms for delaying germination used by seeds.  Well worth looking at.

The effect of water temperature, or some other aquarium conditions on the gender distribution of livebearer offspring.

It is known that egg incubation temperatures can influence the proportion of male and female chicks which hatch, but could this same factor influence the gender of guppies, or other fish which can be easily kept and bread in an aquarium. Guppies are ideal because the male and female fish are so distinct and they readily breed. This experiment would need to be carefully carried out to comply with the guidelines on animal experimentation, but so lond as the conditions were within the natural ranges of the fish this would be fine.

The biggest challenge would be the length of time the fish take to breed, and also managing the conditions so the fish actually do reproduce. Predation of the fry might also be a challenge if there are other fish in the tank, although plenty of vegetation can reduce this.  This is perhaps an investigation idea for a student who already keeps tropical fish, or who is in a school with a lab aquarium.

Does your blood group affect the frequency which you get insect bites, or the severity of the skin's reaction?

This is another investigation idea with which students must be careful to comply with the IB animal experiment guidelines. You must not plan to deliberately cause discomfort to participants, or mosquitoes. But I could imagine that the data might be collected after a evening event where mosquitoes were an irritation and where many of the participants knew their blood groups already.  That means that it's not an idea for everyone.  The principal of the methodology is interesting, although it may be that students with some means of access to a group of medical professionals in an after work barbeque could be the only ones who might try.   It could be a data-base type investigation if the right data cold be found. There is much research on malaria which may prove useful. Remember too that a hybrid study is also possible, where a small sample of experimental can be supplemented with some secondary data.

The effect of body position on heart rate and blood pressure.

The baroreceptor reflex helps to maintain blood pressure at nearly constant levels. The baroreflex uses negative feedback, an increase in blood pressure causes the heart rate to decrease and also causes blood pressure to decrease.  Could the position of the body affect blood pressure and thus heart rate?  This might make an interesting investigation.  Of course controlling other factors which are well known to affect heart rate will be one of the challenges of an investigation into this topic.

Data analysis of body temperature in different groups of people.

If you can find a good data base which provides enough data so that you can choose a part of it (and thus control some variables) it could make a good IA.  A hybrid IA could compare experimental data with a data set published in the biological literature.  Here is a nice example of a set of data, Body temperature data and there are many more suggestions of data sets here: Temperature of a Healthy Human. An interesting option might be to test whether temperatures of a group of people in your school community measured in an experiment are the same as data selected from one of these data sets. Notice that there are interesting differences in 'oral' and 'tympanic' measurements as well as young and old people, males and females, and who knows more. There are plenty of options to investigate; BMI and temperature, mealtimes, time of day, etc.

Testing the effectiveness of a shampoo, anti-tangle product or conditioner on a property of hair.

There are many claims made from producers of hair products which could be tested in an IA.  Does conditioner really make your hair stronger, does a tangle easing product really prevent knots, or reduce friction between hairs?  While it is not permitted to use body fluids in IAs, testing your own hair would be acceptable. To meet the animal experimentation guidelines the hair would have to be collected ethically, without causing pain!  Research into the structure of hair and use of a microscope to study changes in the hairs might also be a useful part of this experiment.

Are the limits of manufacturer's instructions reliable? E;g. the IKEA Växer hydroponic growing system.

Testing the manufacturer's instructions for a growing system could make an interesting IA.  Why does it advise specific types of LED lights? What is the ideal daily light duration? Does changing the chemicals dissolved in the water for the hydrponic system affect plant growth. The challenge of this investigation would be to find a biological reason for a changed variable to have the effect predicted. Obvious one might be light intensity affecting photosynthesis, temperature affeting transpiration or enzymes, or location, fertilizer, type of water used.

What happens after the sell-by date on yoghurt, and other dairy foods?

A simple question in appearance but quite a complex problem. The first aspect to decide would be for which reason are the products past their best.  It could be growth of spoilage bacteria, release of enzymes naturally part of a ripening process, chemical changes from another cause. Of course a specific research question would be needed, but this would probably arise out the choice of food and the background research quite naturally.

Your digital toolkit for Year 12 Science

Table of contents, year 12 science overview.

The big Higher School Certificate year has finally arrived. So what’s on the cards for this year’s studies in the realm of science? Generally, at this point, the big decisions have already been made – it is unlikely students will pick up a science subject in Year 12 that they did not already study in Year 11.

The reason for choosing Science subjects will depend on the student. Many students will be looking to study subjects that clearly point them in the direction of certain career paths or that are prerequisites to courses they hope to work towards in their post high school years. Others may look at the rating system for certain subjects and hope to gain a better HSC result through taking a Science subject, whether it is useful to them or not.

No matter what the reason, science subjects can have the benefit of helping students to expand their thinking and have a better understanding of the way the world works, which can put them in good stead for life in general.

Science is a choice in Years 11 and 12 and most schools and states have different subjects on offer. For the sake of clarity, we will focus on the content of the main four: Biology, Chemistry, Earth and Environmental Science, and Physics.

All about Year 12 Biology

Biology is the study of life in all its forms. Students may find themselves drawn to this subject if they have a love of animals, a fascination with biological systems, or are interested in a pathway towards healthcare, farming or agriculture. The subject involves investigation into biological systems and their interactions, from cellular processes to the dynamics of the ecosystem and beyond.

The two main units in Year 12 are Heredity and Continuity of life, and Maintaining the Internal Environment.

For the first unit, students dive deep into genetics, looking at which biochemical and cellular systems and processes are involved in the transmission of genetic material to the next generation of cells and offspring, and how this happens. Patterns of inheritance are investigated through analysis of genotypes and phenotypes.

In Maintaining the Internal Environment, the focus is on homeostatic responses in organisms in the face of environmental change. This will include study of pathogens and how the invasion of an organism’s internal environment challenges the effective functioning of cells, tissues and body systems, and triggers a series of responses or events to maintain homeostasis.

A look at Year 12 Chemistry

Chemistry investigates materials and substances and the ways in which they transform through interactions and transfers of energy. Students may enjoy this subject for its experimental nature, or if they have a penchant for using test tubes and beakers and applying elements while wearing a lab coat. Mathematical brains may also like this subject as it puts mathematics into practice with scientific equations.

The two main units for Chemistry in Year 11 are Equilibrium, Acids and Redox Reactions, and Structure, Synthesis and Design.

For the former, students use contemporary models to explain the nature of acids and bases, and their properties and uses, and investigate acid-base equilibrium systems and their applications.

In Structure, Synthesis and Design, the principles and application of chemical synthesis, particularly in organic chemistry, are investigated. Students will consider where and how functional groups can be incorporated into already existing carbon compounds, with the aim of generating new substances with properties that can be used in a range of contexts.

A quick trip through Year 12 Earth and Environmental Science

With many facets, it is structured as an overarching field of inquiry that studies interactions between the Earth, water, air and living things and the relationships between these components. This subject has much to do with timescales, with work that looks into the history of the Earth in various ways as well as the processes it undergoes in the present day. It draws upon a range of methods from geology, biology, physics and chemistry, so can be seen as a good all round Science subject with real life application. Students with an interest in conservation or land management may be very keen to study this subject for their own interest as well as their future careers and lifestyles.

The two units included in this subject are Living on Earth – Extracting, Using and Managing Earth resources, and The Changing Earth – The Cause and Impact of Earth Hazards.

For the first unit, students learn how Earth resources are required to sustain and provide infrastructure for life, which then drives demand for biotic, mineral and energy resources. They will explore renewable and non-renewable resources and analyse how resource extraction, use and consumption and associated waste removal affects systems in nature.

In the second unit, students delve into the occurrence of Earth hazards, including volcanic eruptions, earthquakes and tsunami, over a range of time scales and the impacts on Earth systems these can have. They investigate naturally occurring and human-influenced Earth hazards and make predictions of their impacts, as well as identifying strategies for managing and mitigating this.

Physics is a fundamental science used to explain a wide range of natural phenomena in the universe. It provides the foundation of much knowledge used as a basis for other sciences and for many innovations and technologies. Students are likely to enjoy the experiments involved in this area of science and for mathematical minded students, the equations. Much of physics involves learning models, laws and theories and investigating them by analysing and interpreting data.

The two units in Year 12 Science are Gravity and Electromagnetism and Linear Motion and Waves Description.

In the former, students use Newton’s Law of Motion to develop a deeper understanding of motion and its causes, as well as using the gravitational field model to analyse motion on inclined planes, the motion of projectiles, and satellite motion. They will investigate electromagnetic interactions to enable understanding of the operation of direct current (DC) and alternating current (AC) motors and generators, transformers, and AC electricity distribution systems. The production of electromagnetic waves will also be investigated.

For Revolutions in Modern Physics, students learn about how the development of the special theory of relativity and the quantum theory of light and matter were formed through the limitations of existing theories in making observations on relative motion, light and matter. They will also look at how these theories went on to develop the quantum theory of the atom and the Big Bang theory.

Whatever branch of science a student chooses to take, they’re sure to need a solid understanding of content. The skills needed to succeed in science will come from in-class activities, experiments and demonstrations but it’s important to hang those skills on a well-built foundation of science knowledge.

Having an online bank of resources and activities that actually motivates students to revise content will come in handy for both Year 11 and Year 12 science. The stakes are higher now, so setting up an independent “little and often” study program will help Year 12 students get through science with a lot more confidence – and better grades.

Explore EP’s range of quality Year 12 Science learning activities

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Easy Biology Experiments for Kids

April 11, 2023 By Emma Vanstone Leave a Comment

Biology is the study of life and living things , including plants, animals and microorganisms. Biologists refer to living things as organisms. This collection of biology experiments for kids covers some of the most important concepts in biology

There are many different branches of biology, including:

Ecology – the relationships between organisms

Zoology – the study of animals

Taxonomy – classification of organisms

Anatomy – the structure of organisms

Botany – the study of plants

Microbiology – the study of tiny organisms

Physiology – functions of living organisms

Biology is a vast and exciting area of science covering everything from the smallest virus to evolution, ecosystems and the climate.

Top 10 Biology Experiments for Kids

All about water.

All living things need water; luckily, the Earth has a lot of water! Water is made up of one oxygen atom and two hydrogen atoms. This edible model of a water molecule shows the structure.

The yellow sweets represent hydrogen, and the purple sweet represents oxygen. The formula for a water molecule is H 2 O .

Water is a polar molecule. It has a positive end and a negative end. The negative end of one water molecule is attracted to the positive end of another water molecule, resulting in a hydrogen bond between the two molecules. This attraction between water molecules means water has a high surface tension. There are lots of simple ways to demonstrate surface tension. An investigation using a bowl of water with pepper sprinkled over the top is good to start with.

Surface Tension Demonstration

You’ll need.

A bowl of water

Ground black pepper

Washing up liquid ( dish soap )

Instructions

Fill the bowl almost to the top with tap water.

Sprinkle black paper over the surface.

Place a drop of washing-up liquid in the centre of the water.

The pepper should move very quickly to the sides.

How does it work?

The washing-up liquid reduces the surface tension of the water, which allows the water particles at the surface to spread out, taking the pepper with them!

More surface tension demonstrations

Find out how many drops of water you can fit on a coin with Rookie Parenting.

Use surface tension to make lollysticks move in water.

Try the classic magic milk experiment . Adding dish soap makes food colouring in milk explode with colour!

Enzyme Demonstrations

Organisms use enzymes to speed up chemical reactions. Enzymes are biological catalysts. The easiest way to learn about enzymes is to use them! A microorganism called yeast is used in bread making as it contains enzymes that convert sugar and starch ( from the sugar and flour in the bread mix ) into carbon dioxide and ethanol. The carbon dioxide gas makes the dough rise. Giving bread the light, airy texture we all enjoy.

Enzymes only function in the right environment for them, which is different for different enzymes. Yeast needs warm, moist conditions, which is why bread dough is left somewhere warm to rise before baking.

Learn about enzymes with pizza or bread dough

You can learn about the enzymes in yeast by making pizza or bread dough ! If the dough is left somewhere cool, it won’t rise as much as dough left in a warm place, as the enzymes in the yeast won’t work as well.

Cell structure and function activities

All organisms are made up of one or more cells.

Bacteria and protozoa are examples of single-celled organisms.

A group of cells working together is called a tissue. Many tissues working together are an organ.

Cells contain organelles, which allow them to function.

Plant cell models

Making a cell model is a fun way to learn about cell structure.

Jelly/jello or a plate

Candy/sweets

Make your jello as per the instructions in a lightly greased container.

When the jello is set, gently tip it into the container in which you want to make the cell.

Add sweets to look like each organelle.

Use toothpicks and stickers as signs to label the cell model .

Another idea is to combine this activity with the pizza dough to learn about enzymes and create a pizza model of a cell!

Learn more about cells, organelles and the difference between animal and plant cells with my animal and plant cell revision cards.

Specialised cells

Find out about specialised cells with a 3D model of a neurone cell .

Photosynthesis Experiments

Photosynthesis is the process by which organisms ( mostly plants ) create energy. It occurs in organelles called chloroplasts .

Carbon dioxide + water  (and light ) ———> glucose and oxygen

The energy for the reaction comes from sunlight. Photosynthesis is an essential process for life on Earth. It creates oxygen and also helps to remove the carbon dioxide created by human activity.

Plants use the glucose made during photosynthesis for cellular respiration .

Photosynthesis demonstration

Science Buddies have a great photosynthesis investigation you can try.

Plant structure and function

Dissect a flower.

Dissecting a flower is a great way to learn about the different parts of a plant and their function.

Any flowers with large parts – lily, daffodil, tulip

Magnifying glass

Lay the flowers out on a table. Try to identify the different parts.

Label areas of the different parts of a flower on a sheet of white card or paper plate and match the dissected pieces to the correct label.

Another easy way to learn about plant structure and function is to make a 3D flower model .

Osmosis Experiments

Osmosis can be a tricky concept to get your head around as it is the movement of water molecules across a partially permeable membrane from a region of higher water concentration to a region of lower water concentration. This can be demonstrated using an egg!

You might be wondering how on Earth an egg with a shell can be used to demonstrate the movement of water, and you’re right to wonder. The first thing you have to do is remove the shell by soaking the egg in vinegar. The eggshell dissolves, leaving the semi-permeable membrane behind.

Containers big enough to hold an egg

Soak an egg in vinegar for 24 hours. Carefully remove the egg and rinse. You should be able to remove most of the shell. Leave it in vinegar for another 24 hours and then rinse again.

Place the egg in a cup or jar of water and leave for two hours. Water will move into the egg by osmosis as the concentration of water inside the egg is lower than outside. The egg will grow in size.

If the egg is placed in a concentrated sugar solution, water will move out of the egg into the sugar solution as the concentration of water inside the egg is greater than the sugar solution.

More Biology experiments and activities for kids

Find out why surface area to volume ratio is such an important concept in biology using sugar cubes.

Learn about Mitosis with paper plate models.

Extract your own DNA at home!

Demonstrate how diffusion works with squash or food colouring and water.

Make plasticine models of viruses to learn about their structure.

Learn about the structure of DNA with this candy model that shows the double helix structure of DNA.

Find out how trees disperse seeds with my selection of seed dispersal activities .

Model the digestive system with a pair of tights! This is an excellent way for children to really visualise how food passes through the human body.

Make a model of a pumping heart to discover why heart valves are so important.

Biology resources on the web

Learn.Genetics has lots of brilliant resources about genes, human health, neuroscience and ecology.

For younger children, check out Maddie Moate on YouTube . The channel covers topics from finding out how cinnamon grows to beekeeping, all explained in a fun and visual way.

Can you recommend any other biology experiments for kids for us to try?

Last Updated on April 12, 2023 by Emma Vanstone

Safety Notice

Science Sparks ( Wild Sparks Enterprises Ltd ) are not liable for the actions of activity of any person who uses the information in this resource or in any of the suggested further resources. Science Sparks assume no liability with regard to injuries or damage to property that may occur as a result of using the information and carrying out the practical activities contained in this resource or in any of the suggested further resources.

These activities are designed to be carried out by children working with a parent, guardian or other appropriate adult. The adult involved is fully responsible for ensuring that the activities are carried out safely.

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6 Easy Biology Science Experiments for Kids

Let’s dive into studying life and living organisms with a new set of biology experiments for kids! These are all easy and simple to do at home or in your classroom, and all of them are liquid or water-based, so you’ll likely have everything you need on hand to bring these science projects to life. We’ll be exploring osmosis, chromatography, homogenization, transpiration, capillary action, and evaporation.

Related: Check out our other science experiments for kids posts on physics and chemistry !

Gummy Bear Osmosis

“Solute” is a general term that refers to a molecule dissolved in a solution. In a salt water solution, for example, the salt molecules are the solutes. The more salt we put in the solution, the more we increase the concentration of solutes.

Water moves from an area with a lower concentration of solutes to an area with a higher solute concentration. This movement of water molecules is called “osmosis.” In order to examine the process of osmosis and observe how it works, we can look at what happens to gummy bears when they are left to soak in different solutions overnight.

Gummy Bear Osmosis Printable Instructions

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-------------------------------------------------------, what you’ll need:.

• Two container such as bowls, cups, or jars
• Measuring cup
• Gummy bears
• Add ½ cup of water to each of the two empty containers. Add 1 teaspoon of salt to one of the containers and stir well.
• Drop a gummy bear into each container and leave it 8 hours or overnight.
• Observe what happened to each gummy bear. Compare the gummy bears to each other, and also to a gummy bear that was not left to soak overnight.

What’s happening?

The concentration of solutes inside the gummy bear is higher than the concentration of solutes in plain water. As a result, in our experiment, the water flowed into the gummy bear causing it to swell, and that’s why the gummy bear grew overnight.

The same is true for the gummy bear placed in the salt water solution. However, the difference in solute concentration wasn’t as great, so less water flowed into the gummy bear. In other words, it took less water to balance out the solute concentration inside and outside the gummy bear. Thus, the gummy bear in the salt water solution grew less than the bear in the plain water solution.

You can experiment with different solute concentrations to see how it affects the outcome. What happens when you add twice as much salt to the overnight water bath? Is there any amount of salt that can be added to keep the gummy bear the same size?

Exploring Chromatography

Chromatography is a technique used to separate out the components of a mixture. The technique utilizes two phases – a mobile phase and a stationary phase. There are several types of chromatography, but in this experiment, we will be looking at paper chromatography.

In paper chromatography, the stationary phase is filter paper. The mobile phase is the liquid solvent that moves over the filter paper. For this experiment, we will use marker ink to examine how chromatography works.

Exploring Chromatography Printable Instructions

• Three clear containers such as drinking glasses or mason jars
• Coffee filters
• Rubbing alcohol
• Vegetable oil
• Water-soluble marker, any color
• Sharpie marker, any color
• Mark one container with an “A,” a second container with a “W,” and a third container with an “O.” Fill the bottom of the “A” container with rubbing alcohol, the “W” container with water, and the “O” container with vegetable oil. Make sure the liquid in each container comes up no more than ½ an inch from the bottom.
• Take three coffee filters out and measure out 1 inch from the bottom. Mark this spot by drawing a line with the pencil. Make one dot on this line using the water-soluble marker. Do the same with the Sharpie marker.
• Place one coffee filter in each container so that the bottom of the coffee filter is submerged in the solvent but the solvent DOES NOT touch the dots of marker ink. The solvent will travel up the coffee filter and past the dots. Watch what happens to the dots as the solvent moves over them.

Like dissolves like, so substances will interact with solvents that are similar to it. Water-soluble marker ink is polar, so it will interact with polar mobile phases such as water and alcohol. When a non-polar solvent such as vegetable oil moves over it, it will not interact, and therefore will not move.

Sharpie marker ink is “permanent” in the sense that it can’t be washed off with water. It isn’t water-soluble. When the rubbing alcohol moves over it, however, we see that the Sharpie ink interacts with it. This is because Sharpie ink contains alcohols in it. Following the principle of “like dissolves like,” it interacts with the rubbing alcohol.

Using Tie-Dyed Milk to Observe Homogenization

Molecules in a solution tend to aggregate with other molecules that are similarly charged. Fat molecules, for instance, will cluster together with other fat molecules. Milk is made up of different types of molecules, including fat, water, and protein. In order to keep these molecules from completely separating to form layers, milk undergoes a process called homogenization.

Even after undergoing homogenization, however, fat molecules floating free in solution will come together when milk is left sitting undisturbed. To visualize this process, and what happens when those molecules are dispersed, we can use food coloring and dish soap.

Using Tie-Dyed Milk to Observe Homogenization Printable Instructions

• Full fat milk
• 1 small bowl
• Cotton swabs
• Pour some milk into a small bowl. You don’t need a lot of milk for this, just enough to fill the bottom of your bowl. Allow the milk to settle so the surface of the milk is still before moving on to Step 2.
• Add a drop of food coloring to the surface of the milk.
• Dip a cotton swab in dish soap and touch the swab to the surface of the milk, directly adjacent to the drop of food coloring. What happens to the food coloring?

Have you ever tried to mix oil and water? The fat molecules in oil, just like the ones in milk, are “hydrophobic,” meaning they don’t like to be near charged molecules such as water, and will do whatever they can to keep away from them. To achieve this, they clump together. Because the fat molecules are less dense than water, the fat globules float up and form a layer above the water. In our experiment, we added food coloring to this layer of fat globules.

Dish soap is a detergent. Detergent molecules have a hydrophobic end and a hydrophilic end. Because of this, they are able to form a bridge between the fat molecules and the water molecules, causing the fat globules to break up and disperse. What we’re seeing when we add the dish soap is this dispersal of the fat clusters, carrying the food coloring with it and resulting in a beautiful tie-dyed pattern. The result is more dramatic if you add several drops of food coloring and include a variety of colors.

Making water travel through capillary action

Paper towels are designed to pick up spills quickly, absorbing lots of liquid with only a few sheets. But what is it about paper towels that makes them so absorbent? The answer is, in part, capillary action.

In this experiment, we’ll observe how capillary action works to make paper towels efficient. Using nothing but paper towels and the principles governing capillary action, we’ll make water travel from one container and into another.

Making Water Travel through Capillary Action Printable Instructions

• 3 containers (cups or jars)
• Paper towels
• Food coloring
• Line up the three containers. Fill the two containers on either end about ¾ full of water. Add several drops of food coloring to each of the jars. Whatever color you use is up to you, but the effect works best if the two colors combine to make a third color. (For instance – yellow and blue make green.)
• Fold a paper towel in 4 lengthwise. Place one end of the folded paper towel in one of the containers filled with colored water (make sure the end is immersed in the water) and let the other end hang into the empty container. Repeat using a second paper towel and the remaining filled container.
• Let the containers sit for four hours. Check them after 1 hour, 2 hours, and 4 hours. What do you see?

Paper towels are highly porous. These pores function like tiny tubes, or capillaries, to draw up water. Two properties allow this to happen. The first is adhesion. Water molecules are attracted to the walls of the capillaries and “stick” to them. This is enhanced in our experiment because paper towels are made of cellulose molecules that are highly attractive to water. The second property is cohesion. The water molecules like to stick to each other. Together, these two properties allow the water to “travel” along the paper towel against gravity, moving out of one container and dropping into the other.

Efficient paper towels are more porous than less efficient brands, giving them a higher degree of absorbency. Taking this into account, how do you think the progress observed at each time point would differ if you used low quality paper towels instead of highly absorbent ones? How would you expect the color in the middle jar to change if you use a less absorbent paper towel to make the blue water travel, and a more absorbent paper towel to make the yellow water travel?

Observing Xylem in Celery

All plants need water to survive. In order to move water up from the soil and into their shoots and leaves, plants have developed a system of water transport. This system is called “xylem.” We can observe the movement of water through xylem transport by placing stalks of celery in colored water. The colored water moves through the stalk and up into the leaves, making the path of the water through this system visible.

Observing Xylem in Celery Printable Instructions

• A container such as a jar or vase
• Add 1 cup of water to the empty container. Add 2 drops of food coloring to the water (or however many it takes to achieve the color desired) and stir well to mix.
• Choose a celery stalk that has leaves attached to the top. Cut about 1 inch off the bottom of the stalk.
• Place the stalk upright in the container, making sure the bottom of the stalk is immersed in the water.
• Leave the celery out over night. Observe what happens. Take the celery out of the water and cut it open to get a better look at the path the water took.

Plants use a system called xylem to pull water up from the ground and transport it up through the shoot into their leaves. This process is passive, meaning it doesn’t require any energy in order to occur. That’s why the celery was able to pull water up overnight. The celery pulled colored water through its stalk via the xylem transport system. The colored water traveled all the way into the leaves, staining them.

The xylem transport system can be seen more clearly when the celery is cut. The colored water stains the xylem cells, making them visible.

One phenomenon that drives the flow of water through a plant is transpiration. Transpiration is the name given to the process by which water evaporates from the leaves of a plant. What do you think would happen if we repeated the experiment using a celery stalk whose leaves had been cut off? Try it and see!

How to Make it Rain Indoors

One of the properties of water is that it can exist in different phases. It can exist as a liquid, which is the form we’re most familiar with, and it can also exist as a solid (ice), or gas (water vapor). In this experiment, we’ll take water through two of its phases – liquid and gas. We’ll observe how temperature causes water to move from one phase into another. This will allow us to get a better idea of what happens to water in nature, and the role temperature plays in the water cycle.

How to Make it Rain Indoors Printable Instructions

• Large container such as a jar
• A ceramic plate
• Heat approximately eight cups of water to just steaming. This can be done on the stovetop or the microwave, but a stovetop will give you more control over the heating process.
• Pour the water into the jar until it is completely full and allow the jar to sit for five minutes. This will heat the jar for the experiment. After five minutes, discard the water.
• Add enough heated water to fill the jar up approximately halfway. Cover the jar opening with the plate, making sure no steam can escape. Let the jar sit for 3 minutes. Observe what happens to the water in the jar. Note any changes you see.
• After 3 minutes have passed, place enough ice on top of the dinner plate to cover its surface. Watch what happens to the jar.

The water cycle is responsible for producing rain. Liquid water evaporates, sending water vapor into the atmosphere. When the water vapor reaches the cooler air in the upper atmosphere, it condenses back into water droplets, forming clouds. If too much water condenses, or if the temperature becomes colder, the condensed water will fall back down to earth in the form of rain.

In this experiment, we replicated these conditions to produce “rain.” First, we let the heated water form water vapor inside the jar. The water vapor filled the space between the water surface and the plate. We then added ice to our plate, initiating a quick temperature drop. The lower temperature caused the water vapor to condense. This was visible as water droplets that beaded and ran down the sides of the jar. This is how rain happens. We made it rain inside our jar!

You might also like this lesson plan: Learning About Glowing Animals – Bioluminescence or Biofluorescence?

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37 Cool Science Experiments for Kids to Do at Home

General Education

Are you looking for cool science experiments for kids at home or for class? We've got you covered! We've compiled a list of 37 of the best science experiments for kids that cover areas of science ranging from outer space to dinosaurs to chemical reactions. By doing these easy science experiments, kids will make their own blubber and see how polar bears stay warm, make a rain cloud in a jar to observe how weather changes, create a potato battery that'll really power a lightbulb, and more.

Below are 37 of the best science projects for kids to try. For each one we include a description of the experiment, which area(s) of science it teaches kids about, how difficult it is (easy/medium/hard), how messy it is (low/medium/high), and the materials you need to do the project. Note that experiments labelled "hard" are definitely still doable; they just require more materials or time than most of these other science experiments for kids.

#1: Insect Hotels

• Teaches Kids About: Zoology
• Difficulty Level: Medium
• Messiness Level: Medium

Insect hotels can be as simple (just a few sticks wrapped in a bundle) or as elaborate as you'd like, and they're a great way for kids to get creative making the hotel and then get rewarded by seeing who has moved into the home they built. After creating a hotel with hiding places for bugs, place it outside (near a garden is often a good spot), wait a few days, then check it to see who has occupied the "rooms." You can also use a bug ID book or app to try and identify the visitors.

• Materials Needed
• Shadow box or other box with multiple compartments
• Hot glue gun with glue
• Sticks, bark, small rocks, dried leaves, bits of yarn/wool, etc.

#2: DIY Lava Lamp

• Teaches Kids About: Chemical reactions
• Difficulty Level: Easy

In this quick and fun science experiment, kids will mix water, oil, food coloring, and antacid tablets to create their own (temporary) lava lamp . Oil and water don't mix easily, and the antacid tablets will cause the oil to form little globules that are dyed by the food coloring. Just add the ingredients together and you'll end up with a homemade lava lamp!

• Vegetable oil
• Food coloring
• Antacid tablets

#3: Magnetic Slime

• Teaches Kids About: Magnets
• Messiness Level: High (The slime is black and will slightly dye your fingers when you play with it, but it washes off easily.)

A step up from silly putty and Play-Doh, magnetic slime is fun to play with but also teaches kids about magnets and how they attract and repel each other. Some of the ingredients you aren't likely to have around the house, but they can all be purchased online. After mixing the ingredients together, you can use the neodymium magnet (regular magnets won't be strong enough) to make the magnetic slime move without touching it!

• Liquid starch
• Adhesive glue
• Iron oxide powder
• Neodymium (rare earth) magnet

#4: Baking Soda Volcanoes

• Teaches Kids About: Chemical reactions, earth science
• Difficulty Level: Easy-medium
• Messiness Level: High

Baking soda volcanoes are one of the classic science projects for kids, and they're also one of the most popular. It's hard to top the excitement of a volcano erupting inside your home. This experiment can also be as simple or in-depth as you like. For the eruption, all you need is baking soda and vinegar (dishwashing detergent adds some extra power to the eruption), but you can make the "volcano" as elaborate and lifelike as you wish.

• Baking soda
• Dishwashing detergent
• Large mason jar or soda bottle
• Playdough or aluminum foil to make the "volcano"
• Additional items to place around the volcano (optional)
• Food coloring (optional)

#5: Tornado in a Jar

• Teaches Kids About: Weather
• Messiness Level: Low

This is one of the quick and easy and science experiments for kids to teach them about weather. It only takes about five minutes and a few materials to set up, but once you have it ready you and your kids can create your own miniature tornado whose vortex you can see and the strength of which you can change depending on how quickly you swirl the jar.

• Glitter (optional)

#6: Colored Celery Experiment

• Teaches Kids About: Plants

This celery science experiment is another classic science experiment that parents and teachers like because it's easy to do and gives kids a great visual understanding of how transpiration works and how plants get water and nutrients. Just place celery stalks in cups of colored water, wait at least a day, and you'll see the celery leaves take on the color of the water. This happens because celery stalks (like other plants) contain small capillaries that they use to transport water and nutrients throughout the plant.

• Celery stalks (can also use white flowers or pale-colored cabbage)

#7: Rain Cloud in a Jar

This experiment teaches kids about weather and lets them learn how clouds form by making their own rain cloud . This is definitely a science project that requires adult supervision since it uses boiling water as one of the ingredients, but once you pour the water into a glass jar, the experiment is fast and easy, and you'll be rewarded with a little cloud forming in the jar due to condensation.

• Glass jar with a lid
• Boiling water
• Aerosol hairspray

#8: Edible Rock Candy

• Teaches Kids About: Crystal formation

It takes about a week for the crystals of this rock candy experiment to form, but once they have you'll be able to eat the results! After creating a sugar solution, you'll fill jars with it and dangle strings in them that'll slowly become covered with the crystals. This experiment involves heating and pouring boiling water, so adult supervision is necessary, once that step is complete, even very young kids will be excited to watch crystals slowly form.

• Large saucepan
• Clothespins
• String or small skewers
• Candy flavoring (optional)

#9: Water Xylophone

• Teaches Kids About: Sound waves

With just some basic materials you can create your own musical instrument to teach kids about sound waves. In this water xylophone experiment , you'll fill glass jars with varying levels of water. Once they're all lined up, kids can hit the sides with wooden sticks and see how the itch differs depending on how much water is in the jar (more water=lower pitch, less water=higher pitch). This is because sound waves travel differently depending on how full the jars are with water.

• Wooden sticks/skewers

#10: Blood Model in a Jar

• Teaches Kids About: Human biology

This blood model experiment is a great way to get kids to visual what their blood looks like and how complicated it really is. Each ingredient represents a different component of blood (plasma, platelets, red blood cells, etc.), so you just add a certain amount of each to the jar, swirl it around a bit, and you have a model of what your blood looks like.

• Empty jar or bottle
• Red cinnamon candies
• Marshmallows or dry white lima beans
• White sprinkles

#11: Potato Battery

• Teaches Kids About: Electricity
• Difficulty Level: Hard

Did you know that a simple potato can produce enough energy to keep a light bulb lit for over a month? You can create a simple potato battery to show kids. There are kits that provide all the necessary materials and how to set it up, but if you don't purchase one of these it can be a bit trickier to gather everything you need and assemble it correctly. Once it's set though, you'll have your own farm grown battery!

• Fresh potato
• Galvanized nail
• Copper coin

#12: Homemade Pulley

• Teaches Kids About: Simple machines

This science activity requires some materials you may not already have, but once you've gotten them, the homemade pulley takes only a few minutes to set up, and you can leave the pulley up for your kids to play with all year round. This pulley is best set up outside, but can also be done indoors.

• Clothesline
• 2 clothesline pulleys

#13: Light Refraction

• Teaches Kids About: Light

This light refraction experiment takes only a few minutes to set up and uses basic materials, but it's a great way to show kids how light travels. You'll draw two arrows on a sticky note, stick it to the wall, then fill a clear water bottle with water. As you move the water bottle in front of the arrows, the arrows will appear to change the direction they're pointing. This is because of the refraction that occurs when light passes through materials like water and plastic.

• Sticky note
• Transparent water bottle

#14: Nature Journaling

• Teaches Kids About: Ecology, scientific observation

A nature journal is a great way to encourage kids to be creative and really pay attention to what's going on around them. All you need is a blank journal (you can buy one or make your own) along with something to write with. Then just go outside and encourage your children to write or draw what they notice. This could include descriptions of animals they see, tracings of leaves, a drawing of a beautiful flower, etc. Encourage your kids to ask questions about what they observe (Why do birds need to build nests? Why is this flower so brightly colored?) and explain to them that scientists collect research by doing exactly what they're doing now.

• Blank journal or notebook
• Pens/pencils/crayons/markers
• Tape or glue for adding items to the journal

#15: DIY Solar Oven

• Teaches Kids About: Solar energy

This homemade solar oven definitely requires some adult help to set up, but after it's ready you'll have your own mini oven that uses energy from the sun to make s'mores or melt cheese on pizza. While the food is cooking, you can explain to kids how the oven uses the sun's rays to heat the food.

• Aluminum foil
• Knife or box cutter
• Permanent marker
• Plastic cling wrap
• Black construction paper

#16: Animal Blubber Simulation

• Teaches Kids About: Ecology, zoology

If your kids are curious about how animals like polar bears and seals stay warm in polar climates, you can go beyond just explaining it to them; you can actually have them make some of their own blubber and test it out. After you've filled up a large bowl with ice water and let it sit for a few minutes to get really cold, have your kids dip a bare hand in and see how many seconds they can last before their hand gets too cold. Next, coat one of their fingers in shortening and repeat the experiment. Your child will notice that, with the shortening acting like a protective layer of blubber, they don't feel the cold water nearly as much.

• Bowl of ice water

#17: Static Electricity Butterfly

This experiment is a great way for young kids to learn about static electricity, and it's more fun and visual than just having them rub balloons against their heads. First you'll create a butterfly, using thick paper (such as cardstock) for the body and tissue paper for the wings. Then, blow up the balloon, have the kids rub it against their head for a few seconds, then move the balloon to just above the butterfly's wings. The wings will move towards the balloon due to static electricity, and it'll look like the butterfly is flying.

• Tissue paper
• Thick paper
• Glue stick/glue

#18: Edible Double Helix

• Teaches Kids About: Genetics

If your kids are learning about genetics, you can do this edible double helix craft to show them how DNA is formed, what its different parts are, and what it looks like. The licorice will form the sides or backbone of the DNA and each color of marshmallow will represent one of the four chemical bases. Kids will be able to see that only certain chemical bases pair with each other.

• 2 pieces of licorice
• 12 toothpicks
• Small marshmallows in 4 colors (9 of each color)
• 5 paperclips

#19: Leak-Proof Bag

• Teaches Kids About: Molecules, plastics

This is an easy experiment that'll appeal to kids of a variety of ages. Just take a zip-lock bag, fill it about ⅔ of the way with water, and close the top. Next, poke a few sharp objects (like bamboo skewers or sharp pencils) through one end and out the other. At this point you may want to dangle the bag above your child's head, but no need to worry about spills because the bag won't leak? Why not? It's because the plastic used to make zip-lock bags is made of polymers, or long chains of molecules that'll quickly join back together when they're forced apart.

• Zip-lock bags
• Objects with sharp ends (pencils, bamboo skewers, etc.)

#20: How Do Leaves Breathe?

• Teaches Kids About: Plant science

It takes a few hours to see the results of this leaf experiment , but it couldn't be easier to set up, and kids will love to see a leaf actually "breathing." Just get a large-ish leaf, place it in a bowl (glass works best so you can see everything) filled with water, place a small rock on the leaf to weigh it down, and leave it somewhere sunny. Come back in a few hours and you'll see little bubbles in the water created when the leaf releases the oxygen it created during photosynthesis.

• Large bowl (preferably glass)
• Magnifying glass (optional)

#21: Popsicle Stick Catapults

Kids will love shooting pom poms out of these homemade popsicle stick catapults . After assembling the catapults out of popsicle sticks, rubber bands, and plastic spoons, they're ready to launch pom poms or other lightweight objects. To teach kids about simple machines, you can ask them about how they think the catapults work, what they should do to make the pom poms go a farther/shorter distance, and how the catapult could be made more powerful.

• Popsicle sticks
• Rubber bands
• Plastic spoons
• Paint (optional)

#22: Elephant Toothpaste

You won't want to do this experiment near anything that's difficult to clean (outside may be best), but kids will love seeing this " elephant toothpaste " crazily overflowing the bottle and oozing everywhere. Pour the hydrogen peroxide, food coloring, and dishwashing soap into the bottle, and in the cup mix the yeast packet with some warm water for about 30 seconds. Then, add the yeast mixture to the bottle, stand back, and watch the solution become a massive foamy mixture that pours out of the bottle! The "toothpaste" is formed when the yeast removed the oxygen bubbles from the hydrogen peroxide which created foam. This is an exothermic reaction, and it creates heat as well as foam (you can have kids notice that the bottle became warm as the reaction occurred).

• Clean 16-oz soda bottle
• 6% solution of hydrogen peroxide
• 1 packet of dry yeast
• Dishwashing soap

#23: How Do Penguins Stay Dry?

Penguins, and many other birds, have special oil-producing glands that coat their feathers with a protective layer that causes water to slide right off them, keeping them warm and dry. You can demonstrate this to kids with this penguin craft by having them color a picture of a penguin with crayons, then spraying the picture with water. The wax from the crayons will have created a protective layer like the oil actual birds coat themselves with, and the paper won't absorb the water.

• Penguin image (included in link)
• Spray bottle
• Blue food coloring (optional)

#24: Rock Weathering Experiment

• Teaches Kids About: Geology

This mechanical weathering experiment teaches kids why and how rocks break down or erode. Take two pieces of clay, form them into balls, and wrap them in plastic wrap. Then, leave one out while placing the other in the freezer overnight. The next day, unwrap and compare them. You can repeat freezing the one piece of clay every night for several days to see how much more cracked and weathered it gets than the piece of clay that wasn't frozen. It may even begin to crumble. This weathering also happens to rocks when they are subjected to extreme temperatures, and it's one of the causes of erosion.

• Plastic wrap

#25: Saltwater Density

• Teaches Kids About: Water density

For this saltwater density experiment , you'll fill four clear glasses with water, then add salt to one glass, sugar to one glass, and baking soda to one glass, leaving one glass with just water. Then, float small plastic pieces or grapes in each of the glasses and observe whether they float or not. Saltwater is denser than freshwater, which means some objects may float in saltwater that would sink in freshwater. You can use this experiment to teach kids about the ocean and other bodies of saltwater, such as the Dead Sea, which is so salty people can easily float on top of it.

• Four clear glasses
• Lightweight plastic objects or small grapes

#26: Starburst Rock Cycle

With just a package of Starbursts and a few other materials, you can create models of each of the three rock types: igneous, sedimentary, and metamorphic. Sedimentary "rocks" will be created by pressing thin layers of Starbursts together, metamorphic by heating and pressing Starbursts, and igneous by applying high levels of heat to the Starbursts. Kids will learn how different types of rocks are forms and how the three rock types look different from each other.

• Toaster oven

#27: Inertia Wagon Experiment

• Teaches Kids About: Inertia

This simple experiment teaches kids about inertia (as well as the importance of seatbelts!). Take a small wagon, fill it with a tall stack of books, then have one of your children pull it around then stop abruptly. They won't be able to suddenly stop the wagon without the stack of books falling. You can have the kids predict which direction they think the books will fall and explain that this happens because of inertia, or Newton's first law.

• Stack of books

#28: Dinosaur Tracks

• Teaches Kids About: Paleontology

How are some dinosaur tracks still visible millions of years later? By mixing together several ingredients, you'll get a claylike mixture you can press your hands/feet or dinosaur models into to make dinosaur track imprints . The mixture will harden and the imprints will remain, showing kids how dinosaur (and early human) tracks can stay in rock for such a long period of time.

• Used coffee grounds
• Wooden spoon
• Rolling pin

#29: Sidewalk Constellations

• Teaches Kids About: Astronomy

If you do this sidewalk constellation craft , you'll be able to see the Big Dipper and Orion's Belt in the daylight. On the sidewalk, have kids draw the lines of constellations (using constellation diagrams for guidance) and place stones where the stars are. You can then look at astronomy charts to see where the constellations they drew will be in the sky.

• Sidewalk chalk
• Small stones
• Diagrams of constellations

#30: Lung Model

By building a lung model , you can teach kids about respiration and how their lungs work. After cutting off the bottom of a plastic bottle, you'll stretch a balloon around the opened end and insert another balloon through the mouth of the bottle. You'll then push a straw through the neck of the bottle and secure it with a rubber band and play dough. By blowing into the straw, the balloons will inflate then deflate, similar to how our lungs work.

• Plastic bottle
• Rubber band

#31: Homemade Dinosaur Bones

By mixing just flour, salt, and water, you'll create a basic salt dough that'll harden when baked. You can use this dough to make homemade dinosaur bones and teach kids about paleontology. You can use books or diagrams to learn how different dinosaur bones were shaped, and you can even bury the bones in a sandpit or something similar and then excavate them the way real paleontologists do.

• Images of dinosaur bones

#32: Clay and Toothpick Molecules

There are many variations on homemade molecule science crafts . This one uses clay and toothpicks, although gumdrops or even small pieces of fruit like grapes can be used in place of clay. Roll the clay into balls and use molecule diagrams to attach the clay to toothpicks in the shape of the molecules. Kids can make numerous types of molecules and learn how atoms bond together to form molecules.

• Clay or gumdrops (in four colors)
• Diagrams of molecules

#33: Articulated Hand Model

By creating an articulated hand model , you can teach kids about bones, joints, and how our hands are able to move in many ways and accomplish so many different tasks. After creating a hand out of thin foam, kids will cut straws to represent the different bones in the hand and glue them to the fingers of the hand models. You'll then thread yarn (which represents tendons) through the straws, stabilize the model with a chopstick or other small stick, and end up with a hand model that moves and bends the way actual human hands do.

• Straws (paper work best)
• Twine or yarn

#34: Solar Energy Experiment

• Teaches Kids About: Solar energy, light rays

This solar energy science experiment will teach kids about solar energy and how different colors absorb different amounts of energy. In a sunny spot outside, place six colored pieces of paper next to each other, and place an ice cube in the middle of each paper. Then, observe how quickly each of the ice cubes melt. The ice cube on the black piece of paper will melt fastest since black absorbs the most light (all the light ray colors), while the ice cube on the white paper will melt slowest since white absorbs the least light (it instead reflects light). You can then explain why certain colors look the way they do. (Colors besides black and white absorb all light except for the one ray color they reflect; this is the color they appear to us.)

• 6 squares of differently colored paper/cardstock (must include black paper and white paper)

#35: How to Make Lightning

• Teaches Kids About: Electricity, weather

You don't need a storm to see lightning; you can actually create your own lightning at home . For younger kids this experiment requires adult help and supervision. You'll stick a thumbtack through the bottom of an aluminum tray, then stick the pencil eraser to the pushpin. You'll then rub the piece of wool over the aluminum tray, and then set the tray on the Styrofoam, where it'll create a small spark/tiny bolt of lightning!

• Pencil with eraser
• Aluminum tray or pie tin
• Styrofoam tray

#36: Tie-Dyed Milk

• Teaches Kids About: Surface tension

For this magic milk experiment , partly fill a shallow dish with milk, then add a one drop of each food coloring color to different parts of the milk. The food coloring will mostly stay where you placed it. Next, carefully add one drop of dish soap to the middle of the milk. It'll cause the food coloring to stream through the milk and away from the dish soap. This is because the dish soap breaks up the surface tension of the milk by dissolving the milk's fat molecules.

• Shallow dish
• Milk (high-fat works best)

#37: How Do Stalactites Form?

Have you ever gone into a cave and seen huge stalactites hanging from the top of the cave? Stalactites are formed by dripping water. The water is filled with particles which slowly accumulate and harden over the years, forming stalactites. You can recreate that process with this stalactite experiment . By mixing a baking soda solution, dipping a piece of wool yarn in the jar and running it to another jar, you'll be able to observe baking soda particles forming and hardening along the yarn, similar to how stalactites grow.

• Safety pins
• 2 glass jars

Summary: Cool Science Experiments for Kids

Any one of these simple science experiments for kids can get children learning and excited about science. You can choose a science experiment based on your child's specific interest or what they're currently learning about, or you can do an experiment on an entirely new topic to expand their learning and teach them about a new area of science. From easy science experiments for kids to the more challenging ones, these will all help kids have fun and learn more about science.

What's Next?

Are you also interested in pipe cleaner crafts for kids? We have a guide to some of the best pipe cleaner crafts to try!

Looking for multiple different slime recipes? We tell you how to make slimes without borax and without glue as well as how to craft the ultimate super slime .

Want to learn more about clouds? Learn how to identify every cloud in the sky with our guide to the 10 types of clouds .

Want to know the fastest and easiest ways to convert between Fahrenheit and Celsius? We've got you covered! Check out our guide to the best ways to convert Celsius to Fahrenheit (or vice versa) .

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20 Hands-on Biology Activities For Kids

Teaching kids about biology can be a great way to teach them about the world around them and understand the science of life. In this post, we’ll share some easy biology experiments and activities you can do with kids, whether you’re a parent or a teacher. From learning how to build DNA to exploring how plants grow, there are so many fun activities kids will love!

What is Biology?

Biology is the study of living things, and it helps us understand how all living creatures work.

It’s like a big puzzle where scientists, or biologists, try to figure out how plants, animals, and even tiny organisms function. They look at things like how our bodies work, how plants grow, how animals behave, and even how different creatures are related to each other.

Biology covers everything from the tiniest cells that make up our bodies to the vast diversity of life in the world, from the smallest bugs to the biggest whales. It’s like exploring a huge, amazing book about life on Earth. 

Why is it important for kids to study biology?

• Understanding Life : Biology helps kids understand how all living things, including themselves, work. It’s like learning the owner’s manual for living beings.
• Respect for Nature : It teaches kids to appreciate and respect nature, from the tiniest insects to the biggest trees. This respect for the environment is crucial for a sustainable future.
• Healthy Living : Biology teaches about the human body and how to stay healthy. Kids learn about nutrition, exercise, and how to take care of their bodies.
• Curiosity and Discovery : It encourages curiosity and a love for exploring the world around them. Kids get to be little scientists, asking questions and finding answers.
• Environmental Awareness : Biology helps kids understand important topics like climate change, pollution, and conservation. This knowledge empowers them to make the world a better place.

Biology Topics

Plants: Kids can learn about different types of plants, their parts (roots, stems, leaves, flowers), and how they grow. They may also explore the importance of plants in providing food and oxygen for living beings.

Animals: Biology involves studying various animals and their characteristics. Kids can learn about the diversity of animals, their habitats, and how they adapt to survive in different environments.

Human Body: Basic concepts of the human body, such as organs, bones, muscles, and the five senses, can be introduced. Kids can learn how their bodies work and how to keep themselves healthy.

Life Cycles: Biology includes understanding life cycles of different organisms, like butterflies, frogs, and plants. Kids can observe and discuss the stages of growth and development.

Habitats and Ecosystems: Children can explore different habitats, such as forests, deserts, oceans, and learn about the plants and animals. They can also understand the interconnections between living things in an ecosystem.

Microscopic World: Kids can be introduced to the fascinating world of microscopic organisms, such as bacteria and protozoa. They may learn about their importance in nature and human health.

Genetics: In simple terms, genetics can be explained as the study of how traits are passed from parents to offspring. Kids can understand basic inheritance patterns and family resemblances.

Food Chains and Webs: Biology involves exploring food chains and food webs, showing how energy flows from one organism to another in an ecosystem.

Adaptations: Kids can learn how different animals have adaptations that help them survive in their environments, such as camouflage or unique body features.

Nature Observations: Encouraging kids to observe and explore the natural world around them is an integral part of biology. Nature walks, and outdoor activities foster a deeper appreciation for living organisms.

Free Biology Experiments Guide

Download and save this handy biology experiments guide and science process pack for your next science lesson!

Fun Biology Questions to Ask

• What is photosynthesis, and how do plants use it?
• How do animals adapt to their environments?
• What’s the purpose of the heart in our bodies?
• How do bees help flowers and plants grow?
• Why do we have different seasons, and how does that affect nature?
• How do animals communicate with each other?
• What’s the role of DNA in living organisms?
• How do animals like chameleons change their colors?
• What are ecosystems, and why are they important?
• What are the 5 senses of the body? Think of fun examples for each one!

Quick Toddler or Preschooler Biology

• Start with easy ideas like recognizing common animals, plants, or body parts using pictures and simple books.
• Plan activities like planting seeds or observing bugs. Kids learn biology through play and exploration.
• Explain things in everyday language. For example, say, “Plants use sunlight for their food” instead of using complex words.
• Encourage thinking by asking questions like, “Why do leaves change color in the fall?” It helps kids explore and wonder.
• Go on nature walks to see plants and animals. Talk about what you see and how they act.
• Share nature stories. Kids remember better when learning is part of a story.
• Talk about the 5 senses or do an All About Me activity!

Biology Life Cycle Activities

💡New for the Holidays: Reindeer Facts and Life Cycle for Kids

• Life Cycle Bug Play Dough Mats
• Ladybug Life Cycle
• Frog Life Cycle
• Butterfly Life Cycle
• Penguin Life Cycle
• Bean Sprout Life Cycle
• Plant Life Cycle
• Bee Life Cycle
• Earthworm Life Cycle
• Pine Tree Life Cycle
• Reindeer Life Cycle and Facts

Biology Experiments To Explore

Explore osmosis.

Kids can discover how water moves in and out of plant cells in this  Potato Osmosis Lab . You can also demonstrate this with growing gummy bears !

Make A Heart Model

Create an engaging and educational  Heart Model STEM Project  with your kids using household items like plastic bottles, bendy straws, and clay.

Extract DNA From Strawberries

Learn  how to extract DNA from strawberries  in this fun and educational science experiment that uncovers the secrets of DNA and genetics. 

Build A Candy DNA Model

Explore how to build a  Candy DNA model  with this fun and educational edible science activity, perfect for teaching kids about the structure of DNA using candy-like licorice and marshmallows. Make sure to also grab this DNA coloring sheet .

Make A Lung Model

Kids can learn  how to make a lung model , which involves creating a simple lung model using a plastic bottle, balloons, and a straw to demonstrate how lungs function when we breathe.

X-Ray Project

Explore the principles of X-rays inspired by scientist Marie Curie’s groundbreaking work, and make your own X-rays with this hands-on STEAM project .

Create A Seed Jar

Explore the fascinating world of seed germination, watch roots grow, and identify the parts of a plant with this  Seed Germination Experiment .

Build A Mini Greenhouse

Enjoy growing plants with a mini greenhouse made from plastic bottles . Watch the life cycle of a plant unfold with simple materials from your recycling bin.

Explore Leaf Chromatography

Discover the science of  leaf chromatography  with this STEM activity that teaches kids about the pigments in leaves and how they change colors during the fall season.

Make Spinach Glow

Transform ordinary spinach that you eat into a glowing green mixture under ultraviolet light! Learn about the pigments present in plants, particularly chlorophyll and how certain pigments can absorb light at one wavelength and emit light at another, resulting in the observed glow.

Dissect A Flower

Learn about the parts of a flower and what they do with a fun printable parts of a flower diagram ! Then gather your own flowers, and do a simple flower dissection to identify and name the parts of a flower.

Color Celery

Set up a  celery experiment with food coloring that shows how water travels through a plant.

Explore How Plants Breathe

Learn about plant respiration with a few leaves you can grab from your backyard.

Make Red Cabbage Indicator

Find out how cabbage can be used to test liquids of varying acid levels. Depending on the pH of the liquid, the cabbage turns shades of pink, purple, or green!

Explore Leaf Veins

Learn about the structure of plant leaves and  how water travels through leaf veins . This fun and simple biology experiment is a great way to see behind the scenes of how plants work!

Explore the world of  germs  by learning about hand hygiene and the importance of proper handwashing techniques using bread.

Make Blubber

How do whales, polar bears or even penguins stay warm? Make blubber and test out how it works as an insulator with this  blubber experiment .

Bonus: Printable Biology Worksheets

Learn about where different animals live and various biomes with these  printable biomes  of the world  lapbook project.

Nitrogen Cycle

Discover the fascinating world of the  nitrogen cycle  and the important role micro-organisms have in this process.

Carbon Cycle

Kids can learn all about the Carbon Cycle and witness the exchange of carbon through various processes.

Animal and Plant Cells

Explore the parts of the animal cell or the plant cell with this simple STEAM project. Or grab the complete Animal and Plant Cells Project Pack here.

Learn all about the double helix structure of DNA with this printable DNA coloring worksheet ! Color in the parts that make up DNA, as you explore our amazing genetic code.

Photosynthesis

Green plants make their own food, and food for us through the process of photosynthesis. Use these photosynthesis worksheets to introduce the steps of photosynthesis.

Pollinators

Explore the important role of pollinators in the reproduction of flowering plants with our printable pollinator activity guide.

Food Chains

These printable food chain worksheets are a great way to learn about the flow of energy through simple food chains in ecosystems.

Animal Adaptions

Find instructions and templates to explore animal adaptions in our printable Animal Adaptations Project Pack .

Animal Migration

Dive into the amazing world of animal migration, and the incredible journeys animal embark on all over the world. Printable activities, and facts.

Add these fantastic reptile worksheets to your study of the animal kingdom, and use them to put together a lapbook project about the fascinating world of reptiles.

Vertebrates and Invertebrates

These printable vertebrate and invertebrate worksheets provide a fun way to learn about two different groups of animals.

Why Do Leaves Change Color

Find out what causes leaves to change color in the fall with this fun  Why Do Leaves Change Color lapbook project.

How to Set Up a Biology Project

Want to turn one of these fun biology activities into a science fair project? Then, you will want to check out these helpful resources.

• Easy Science Fair Projects
• Science Project Tips From A Teacher
• Science Fair Board Ideas

Printable Science Projects For Kids

If you’re looking to grab all of our printable science projects in one convenient place plus exclusive worksheets and bonuses like a STEAM Project pack, our Science Project Pack is what you need! Over 300+ Pages!

• 90+ classic science activities  with journal pages, supply lists, set up and process, and science information.  NEW! Activity-specific observation pages!
• Best science practices posters  and our original science method process folders for extra alternatives!
• Be a Collector activities pack  introduces kids to the world of making collections through the eyes of a scientist. What will they collect first?
• Know the Words Science vocabulary pack  includes flashcards, crosswords, and word searches that illuminate keywords in the experiments!
• My science journal writing prompts  explore what it means to be a scientist!!
• Bonus STEAM Project Pack:  Art meets science with doable projects!
• Bonus Quick Grab Packs for Biology, Earth Science, Chemistry, and Physics.

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~ projects to try now ~.