Biology
Biology projects for class 6 to 8: 81 ideas.
Each project below opens to its own page with what it shows, the science behind it, the materials, safety, step-by-step instructions, what you should see and viva questions. Many can be made from things at home; where a kit helps, the page links one.
Other subjects for class 6 to 8: Physics, Chemistry, Maths, Earth and space, Electronics and robotics, Environment, Computing and coding.
What do seeds need to sprout?
Seeds need water, air and warmth to germinate. Most seeds sprout even in the dark, but the seedlings need light to turn green and keep growing.
Human digestive system model
Food travels from the mouth down the food pipe to the stomach, the small intestine and the large intestine. The liver and pancreas add juices that help digestion.
Working lungs model
Pulling the diaphragm (the stretched balloon) down makes more space in the chest, the air pressure inside drops, and air rushes into the lungs. Pushing it back up pushes the air out.
Human heart model with double circulation
The heart has four chambers. The right side pumps blood to the lungs to pick up oxygen, and the left side pumps it to the rest of the body. Valves stop the blood flowing backwards.
Plant and animal cell models
Both cells have a nucleus, cytoplasm and a cell membrane. Plant cells also have a cell wall, chloroplasts and a large vacuole.
Turn a sprouting seed sideways: do roots still grow down?
When a sprouting seed is turned on its side, the root bends to keep growing downwards and the shoot bends upwards. Plants sense gravity, and the response is called gravitropism (or geotropism).
Shoebox maze: a bean shoot finds its way to the light
A bean shoot growing inside a dark shoebox with one small hole turns and twists around cardboard walls until it reaches the light. Plants grow towards light, a response called phototropism.
Plastic bag over a leafy twig: collect the water leaves give off
A clear bag tied over a leafy branch fills with droplets within a few hours, while a bag over a bare branch stays dry. Leaves lose water vapour through tiny pores (stomata), a process called transpiration.
Foil on a leaf: where does the plant store starch?
A leaf partly covered with foil for two days and then tested with iodine turns blue-black only where light reached it. Leaves make starch by photosynthesis, and photosynthesis needs light.
Human skeleton from cardboard tubes, straws and bottle caps
A life-size or half-size skeleton built from waste shows the main bones of the body, how the skull protects the brain, how the ribs make a cage around the heart and lungs, and where the joints let us bend.
Cardboard arm with rubber-band biceps and triceps
Two rubber bands or balloons fixed across a hinged cardboard arm show that muscles work in pairs: when the biceps shortens the arm bends, and when the triceps shortens the arm straightens. Muscles can only pull, never push.
Bread mould in sealed bags: damp, dry, warm and cold
Slices of bread sealed in bags under different conditions show that mould grows fastest on damp bread in a warm place and hardly at all on dry bread or in the fridge. Mould is a fungus that grows from spores already present in the air.
Eggshells in cola, juice, milk and water: a tooth decay model
Eggshells soaked in cola and fruit juice soften, stain and lose material within days, while shells in milk and water stay hard. Eggshell, like tooth enamel, is a hard mineral that acids slowly dissolve, so sugary and acidic drinks harm teeth.
Balcony bird diary: a 2 week tally of the birds around you
Watching the same spot for 15 minutes each morning and evening and tallying every bird seen shows which species live nearby, when each is active and what it eats. The diary becomes a small record of local biodiversity.
Ant trails: which foods do ants choose and how do they find them?
Tiny drops of sugar water, salt water, oil and plain water set out near an ant trail show which foods ants prefer and how a few scouts quickly bring many workers along a chemical trail. Rubbing a finger across the trail breaks it and the ants lose their way for a while.
Who lives in a handful of garden soil? A white tray survey
Spreading soil from a garden bed, a compost heap and bare ground on white trays and counting the earthworms, beetles, millipedes, ants and springtails shows that living soil is full of animals and that richer soil has more of them.
Celery stalk in coloured water: how water climbs a stem
Plants pull water up through thin tubes in their stems. When the water is coloured, the colour travels up inside the stalk and shows exactly where the tubes run, all the way to the leaves.
White flower with a split stem that drinks two colours
A single white flower can turn two colours when its stem is split and each half drinks a different dye. It shows that water travels in separate channels all the way up to the petals.
Three bean pots: too little, enough and too much water
A plant needs the right amount of water, not the most. Roots in soggy soil lack air and plants in dry soil lack water, so only the middle pot grows well.
Crowded or spaced: do seedlings compete for light and space?
Plants growing close together share the same light, water and soil, so each one has less. Comparing a crowded tray with a spaced tray shows how competition changes growth.
Tall cup and short cup: does root room change growth?
The depth and amount of soil limit how far roots can spread. Growing the same bean in a tall cup and a short cup shows how room for roots affects the plant above ground.
Ear model with a funnel and balloon eardrum and dancing salt
Sound is collected by the outer ear and makes the eardrum vibrate. A balloon stretched over a tube acts as the eardrum, and grains of salt dance on it when you speak into the funnel.
Shoebox eye model with a lens that shows an upside-down image
The eye works like a camera. A lens at the front focuses light from the world onto a screen at the back, giving a small image that is upside down.
Blind spot card: finding the place where your eye cannot see
Each eye has a small spot with no light-sensing cells, where the optic nerve leaves the eye. A card with a cross and a dot lets you find the distance at which the dot disappears.
Is there a tongue map? Testing sweet, salt, sour and bitter
The old school picture of a tongue with separate zones for each taste is a myth. Testing tastes on different parts of the tongue shows that every part can detect all the basic tastes.
Two-point touch test on fingertip, palm and forearm
Our skin is not equally sensitive everywhere. The smallest gap at which a person feels two points instead of one shows where touch receptors are packed more closely.
Ruler-drop reaction time: does practice or distraction change it?
A dropped ruler measures how fast your nerves and muscles respond. How far the ruler falls before you catch it gives your reaction time, and you can test how practice or a second task changes it.
Pulse rate before and after exercise: a recovery graph
Muscles in exercise need more oxygen and glucose, so the heart beats faster. The time that the pulse takes to come back to normal shows how quickly the body recovers.
Funnel and tube stethoscope to hear the heartbeat
A funnel and a rubber tube can carry the sounds of the heart to your ear. You hear a steady lub-dub that is made as the heart valves close.
Blood in a bottle: plasma, red cells, white cells and platelets
Blood is made of a pale yellow liquid, plasma, with red cells, white cells and platelets floating in it. A sealed bottle with beads shows the parts and their rough amounts.
Four body joints from waste: ball, hinge, pivot and gliding
Where two bones meet, a joint lets them move in a particular way. Models made from waste show how a ball and socket, a hinge, a pivot and a gliding joint each allow a different movement.
Tea-stained eggshell: water, brush or toothpaste, which cleans best?
Foods and drinks can stain the surface of teeth, and brushing removes the stain. Stained eggshells stand in for teeth to compare rinsing, brushing with water and brushing with toothpaste.
Fat spot test on brown paper: nuts, snacks, fruit and sweets
Foods that contain fat leave a see-through greasy mark on brown paper that does not dry away. A quick rub test sorts foods into those with fat and those without.
Banana ripening in bags: does a ripe fruit speed it up?
Ripening fruits release a gas called ethylene that makes nearby fruit ripen faster. Green bananas sealed with a ripe fruit ripen sooner than bananas left on their own.
Idli batter rise diary: a warm corner against a cool corner
Rice and urad dal batter swells and turns sour overnight because tiny microbes in it make gas and acid. The rise is faster in a warm place than in a cool one.
Curd setting time at three temperatures
Milk turns into curd because friendly bacteria in a spoon of old curd turn milk sugar into lactic acid. Keeping the milk at different temperatures shows how heat changes the speed of this change.
Paddy field food web as a hanging mobile with who-eats-whom threads
In a paddy field many food chains join into a web. A hanging mobile with threads showing who eats whom makes it easy to see how energy passes from rice plants to the top animals.
Closed bottle garden that recycles its own water
A sealed jar with soil and plants keeps its own small water cycle. Water evaporates from the soil and leaves, condenses on the glass and runs back, while plants and soil life swap oxygen and carbon dioxide.
Flower visitor watch: counting pollinator visits by colour and time of day
Many flowers depend on insects, birds or bats to move pollen so they can make fruit. Counting visitors on two kinds of flower at different times of day shows which flowers and hours are busiest.
Bamboo, pine cone and brick insect hotel for garden helpers
Many helpful insects, such as solitary bees, need small holes to nest or shelter. A hotel made from waste gives them a safe place and lets you observe from a distance who moves in.
Seed travel models: wind wing, fluff parachute, floating husk, hook and spring
Plants spread their seeds far from the parent so the young plants have room to grow. Paper and cloth models copy how wind, water, animals and bursting pods carry seeds.
Onion peel slide: cell wall, nucleus and the size of one cell
The thin skin of an onion layer is a sheet of box-like plant cells. A stained slide under the microscope shows the cell wall and the nucleus, and a simple trick lets you estimate how big each cell is.
Plant cell model in a foil tray with clay organelles
A plant cell has a rigid cell wall, a cell membrane, a nucleus, a large vacuole and green chloroplasts. The model shows where each part sits and what job it does.
Bottle, balloon and straw model of the lungs and diaphragm
Breathing happens because the diaphragm moves down and the chest space grows, which lowers the pressure inside so air rushes in. Pushing the diaphragm up squeezes the lungs and air leaves.
Digestive system model with a stocking and a bottle stomach
Food travels through one long tube, the alimentary canal, and is broken down by chewing, stomach juices and absorption in the small intestine. The model shows the order and lengths of the parts.
Self-watering bottle planter that waters itself with a cotton wick
Water climbs up a cotton wick by capillary action, which moves it from the lower tank to the soil without any pump. Plants take what they need and the tank lasts several days.
Paper plate food chain and food web spinner
Energy passes from the Sun to plants and then to animals that eat them. The spinner shows who eats whom and why the chain starts with a producer.
Cardboard flower with removable parts that shows pollination
A flower has sepals, petals, stamens and a pistil. Pollen travels from the stamen to the stigma, which starts the making of seeds.
Which bag ripens bananas faster? Ethylene gas at home
Ripe fruits release a gas called ethylene that makes other fruits ripen faster. By keeping green bananas in different bags and with a ripe fruit, you see how trapping this gas speeds up ripening.
How much water do chana and rajma soak up in a night?
Dry seeds take up water through their seed coat by imbibition, swelling and gaining weight. By weighing dry and soaked pulses at fixed times you plot how fast and how much they absorb, and why soaking helps cooking and sprouting.
Hydroponic mint and spinach grown in a cut bottle with no soil
Plants can grow with their roots in nutrient water instead of soil. A bottle hydroponic setup shows that roots need water, nutrients and air, not soil itself.
Cotton wick self-watering planter: how long can a plant go unwatered?
A wick moves water from a reservoir into the soil by capillary action. A plant in a wick pot stays healthy while a normal pot dries out, which shows how to save water and look after plants during holidays.
Compost, vermicompost and plain soil: which grows beans best?
Organic manures add nutrients and improve the soil. Growing the same bean in plain soil, compost and vermicompost shows the effect of each on growth.
Ant repellents compared: turmeric, chalk, clove powder and vinegar line
Ants follow chemical trails and avoid some household substances. Counting how many ants cross a line of each substance gives a safe test of natural repellents.
Class seed bank of local varieties with germination record cards
Saving seeds of local vegetables, pulses and flowers keeps variety alive. A record card for each seed packet teaches how farmers collect, dry, label, store and test seeds.
Thali balance survey: what food groups does a class eat at lunch?
A balanced meal has foods from several groups: cereals, pulses, vegetables, fruit, and milk products. A survey of lunch boxes shows which groups most students eat and which they miss.
Pulse rate and recovery time after skipping, plotted on a graph
The heart beats faster during exercise to supply more oxygen to muscles. After stopping, the pulse falls back to its resting rate, and the time it takes is a simple sign of how the body recovers.
Breaths per minute at rest, after stairs and after a short run
Breathing rate increases with activity because the body needs to take in more oxygen and release more carbon dioxide. Counting breaths gives a simple measure of this change.
School bag weight and standing posture: a photo and tape-measure survey
Heavy bags can change the way a student stands, with the head and shoulders leaning forward. Measuring bag weight as a share of body weight and checking posture in side photos gives data to discuss a safe bag load.
Does washing longer remove more? A 5, 10 and 20 second hand-wash test
Soap helps to lift dirt and oily grime off the skin, and rubbing for longer removes more of it. A harmless coloured powder stands in for germs so that you can see how much is removed in a given time.
Hidden sugar in cold drinks shown as spoonfuls on the table
Many drinks carry a lot of sugar. By converting the grams on the label into teaspoons of sugar, you can see in a vivid way how much sugar is in a glass.
Reading food labels: comparing three biscuits per 100 g
Packaged foods list energy, fat, sugar, protein and salt on the label. Comparing foods fairly means using the per 100 g column and not the per pack figure, which depends on pack size.
Class water diary: how much do students drink on a hot school day?
Water is lost through sweat, breath and urine, and has to be replaced by drinking and by the water in food. A diary of how much students drink shows the range between individuals and how heat affects it.
Eggshell tooth test: which drinks stain and soften it overnight?
An eggshell is made of calcium carbonate like tooth enamel is mostly calcium minerals. Soaking shells in different drinks shows which ones stain and which ones soften the shell, a model for why teeth need care.
Pupil size in bright and dim light, measured with a mirror and ruler
The pupil gets smaller in bright light and larger in dim light, an automatic reflex that protects the eye and helps it see. A mirror and a ruler let you measure this change without any special equipment.
Paper-cup stethoscope for listening to a heartbeat and counting it
Sound from the heart is passed through the chest and can be gathered by a cup, which makes it louder in your ear. Counting the beats gives the heart rate.
One-leg balance time with eyes open, eyes closed and a moving floor
Balance uses signals from the eyes, the inner ear, and the muscles and joints. Taking away the vision signal makes balancing much harder, which shows how the senses work together.
Sprouting moong and chana: a five-day length and weight log
Soaked seeds wake up, absorb water and start to grow roots and shoots. Measuring weight and sprout length every day shows how quickly the seed changes, and why sprouts are a popular food.
Nature walk collection tray with labels
Plants and their parts come in many sizes, shapes and colours. Collecting and sorting fallen things makes us look closely and notice differences.
Does a plant lean towards the window light?
Plants grow towards light. A seedling kept by a window bends towards it, and turns back if we turn the pot around.
Heartbeat count: resting and after 20 jumps
The heart beats faster when the body works harder. We can feel the pulse and count it to see the change.
How big is my breath? Blowing up a balloon
Our lungs hold air. We can compare how much air different people can blow out in one breath by measuring a balloon.
Fingerprint cards: loops, whorls and arches
Every person has a different pattern of ridges on their fingertips. The patterns fall into a few main types: loops, whorls and arches.
Regrowing carrot and beetroot tops in a shallow dish
Plants store food in roots like carrot and beetroot. If the top is kept in water, it uses that stored food to sprout new leaves.
Matchstick pulse indicator: heart rate before and after exercise
Each heartbeat pushes a wave of blood through the arteries, and at the wrist this wave makes a tiny matchstick rock. Counting the rocks for a minute gives the pulse rate, which rises after exercise because the muscles need more oxygen.
Funnel and rubber-tube stethoscope that lets you hear a heartbeat
A funnel gathers the faint sound of the heart and the tube guides it to the ear, so a heartbeat sounds louder than it does through the air. You hear two sounds, lub and dub, made by the heart valves closing.
Ruler-drop reaction time: how fast does a signal travel from eye to hand?
Catching a falling ruler needs the eye, brain, nerves and muscle to work together, and the distance it falls before you catch it gives your reaction time. Using the free fall formula the distance is converted to a time of about 0.15 to 0.25 seconds.
Blind spot card: finding the place in your eye that cannot see
Where the optic nerve leaves the retina there are no light-sensing cells, so a small spot in each eye cannot see. A cross and a dot on a card show the dot vanishing when its image falls on this blind spot.
Card microscope with a water-drop lens to see onion peel cells
A tiny drop of water held in a hole acts like a strong magnifying lens, and with it the brick-like cells of an onion peel can be seen. It shows that all living things are made of cells.
Touch-me-not (Mimosa) plant: timing how long leaves take to close and reopen
The leaves of the touch-me-not plant fold up within seconds of being touched and open again after a few minutes. This shows that plants also respond to stimuli, but through changes in water pressure in cells rather than through nerves.
Hydrotropism tray: do pea roots grow towards damp cotton?
Plant roots can bend towards moisture, a response called hydrotropism, even when gravity pulls them straight down. A tray with a damp side and a dry side shows roots growing toward the water.