This fun and creative activity helps children visualise a Butterfly's Life Cycle by encouraging them to think of edible items to represent each stage of the cycle.

This activity would be great for younger children to read alongside The Very Hungry Caterpillar, too!

Don't forget I have lots more kitchen science experiments to try if you enjoy this one!

The Butterfly Life Cycle

The life cycle of a butterfly has four stages, each lasting anywhere between one month and a whole year!

Stage 1 - Butterfly Egg

The first stage is the egg. Butterfly eggs are very small and round or oval. If you look carefully, you might even see a teeny tiny caterpillar growing inside them! The actual shape of the egg depends on the type of butterfly inside. Butterfly eggs are laid on leaves.

Stage 2 - Caterpillar ( Larva )

We call butterfly larvae caterpillars. Caterpillars hatch from the tiny eggs in stage 1. Caterpillars mostly eat!

Did you know that mother butterflies lay their eggs on a type of leaf their caterpillars like to eat? This is because caterpillars cannot easily travel to find a source of food they like.

The skin of a caterpillar doesn't grow with the caterpillar, so they shed their skin several times as they grow.

The caterpillars you can see below are from an Insect Lore Butterfly World set. I would 100% recommend buying one. Releasing the adult butterflies into the world was amazing, and the whole process was fascinating to watch.

Stage 3 - Chrysalis ( Pupa )

Once the caterpillar is fully grown, it forms a pupa or chrysalis around itself. Inside the chrysalis, a transformation called metamorphosis occurs.

Stage 4 - Butterfly

Once the process of metamorphosis is complete, the butterfly emerges from the chrysalis!

Female adult butterflies reproduce and lay eggs on leaves, ready for the life cycle to start again.

Egg – Caterpillar – Chrysalis - Butterfly

How to make an edible butterfly life cycle

What you’ll need

Marshmallows, yoghurt raisins, eggs

Sweet Caterpillars, spring onion – caterpillars – you could use two different sizes here to show how the caterpillar grows.

Liquorice, long marshmallows, physalis - chrysalis.

Pasta bows, orange segments - butterfly

Use a paper plate or use my FREE printable life cycle.

Instructions for Butterfly Life Cycle

Look at all the items you have available and find the best match for each life cycle stage.

Place the items in the correct order on a paper plate and add arrows to show the direction of change.

Ask a friend if they can tell what each stage represents.

Caterpillars often shed their skin and eat lots of leaves. Can you add these stages to your life cycle?

Extension ideas

Try using fruit and vegetables to make a butterfly life cycle model.

Create an edible life cycle for a frog or ant.

Butterfly wings are symmetrical; practice drawing a symmetrical butterfly.

More Science for Kids

Find out what dinosaurs ate by making dino poop!

Make a flowering plant life cycle plate!

Science concepts

Metamorphosis

Lifecycles

Suitable for Key Stage 2 Science

Living Things and Their Habitats

Affiliate links

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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

1. Candy DNA Model

This candy DNA model is a great way to learn about the double helix structure of DNA and tastes great, too!

2. Colourful flowers - transpiration investigation

Place white flowers in a pot of food colouring and water to change their colour. This activity is a brilliant visual way to learn about transpiration and transport in plants.

3. Investigate the effect of increasing temperatures on transpiration

Use celery and food colouring to find out how increasing temperature affects the rate of transpiration in plants.

4. Osmosis and eggs

Learn about osmosis with an egg without a shell. The shell is removed by soaking the egg in vinegar. Place the egg in water and watch it grow in size as water moves into it.

This is a fantastic visual way to demonstrate osmosis that always makes a big impact.

5. Edible butterfly life cycle

Make an edible butterfly life cycle using fruit, vegetables, pasta or sweets.

6. What Did Dinosaurs Eat? – Dinosaur Poop Investigation

Discover what dinosaurs ate with a fun dinosaur poo investigation! This is a wonderful activity for younger children who love searching through the playdough for clues to what dinosaurs ate.

7. How does exercise affect heart rate?

Find out how exercise affects heart rate with a simple investigation where children measure their heart rate before and after exercise.

8. What are teeth made from?

Use eggs to find out what teeth are made from and discover the food items that cause them to stain or decay.

9. Digestive system model

Model the digestive system with biscuits, orange juice and tights. This is a slightly gross activity that kids of all ages will love.

10. Make a model lung

Find out how lungs work with a DIY lung model made from a plastic bottle, straw and balloon.

That's my personal top 10 biology experiments, but there's plenty more! Learn about water, cells, plants, enzymes and surface tension with the activities below.

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 H₂O.

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.

You'll need

Jelly/jello or a plate

Candy/sweets

Instructions

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.

You'll need

Any flowers with large parts - lily, daffodil, tulip

Magnifying glass

White card

Tweezers

Scissors

Instructions

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.

You'll need

Two eggs

Containers big enough to hold an egg

Vinegar

Water

Sugar

Instructions

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?

The post Easy Biology Experiments for Kids appeared first on Science Experiments for Kids.

Birds can fly because they have wings, a streamlined body, strong muscles and very light, hollow bones.

The bones of birds are very strong and adapted perfectly to flight. They have a dense, strong exterior and an interior strengthened with criss crossing ridges and webbing. The hollow interior isn't just to reduce the weight of the bone. Bird bones are filled with air sacs which connect to thier respiratory system allowing oxygen exchange so the lungs of the bird have a constant supply of air for respiration. Birds are energetic creatures so have a high oxygen demand.

Science Activities for learning about Birds

Strong Hollow Bird Bone Science Experiment

This simple science activity demonstrates how strong a hollow bone shape can be.

You'll need

Paper

Tape

Books

Paper plate

Instructions

Roll one piece of paper into a circular column, one into a triangle column and one into a square column.

Stand the circular column up first and place books on the top until it collapses. Repeat with the other two shapes using the same books in the same order.

You should find the circular column is the strongest, as it doesn't have any edges so the weight is spread evenly through the column.

As an extension activity roll three circular columns and place the paper plate on top of them. Place books on the plate until the columns collapse.

Are you surprrsed how strong a basic hollow column is?

More bird themed science activities

Find out why birds have different shaped beaks with a simple sorting activity.

Help local birds survive the winer months by making a bird feeder.

Read more about the air sac system of birds.

Fun bird facts

Feathers allow birds to move smoothly through the air.

Hummingbirds beat their wings 50 times a second. As the wings move they make the humming noise that gives them their name.

A birds feathers are called its plumage.

Birds lay eggs in a nest to help keep them safe. The nests of the bald eagle can be up to 2.5 metres wide!

Woodpeckers peck at trees to get to small insects that live in the bark.

A woodpecker beak is strong enough to make a hole in the tree big enough for a nest.

Cuckoos lay thier eggs in other birds nests!

A skimmer has a beak shaped like scissors. This allows it to catch fish just below the surface of water.

Which birds don't fly?

Some examples of birds that don't fly are:

Ostriches

Penguins

Kiwis

Emus

The post How do birds fly? appeared first on Science Experiments for Kids.

Do you know you can change the colour of white flowers by placing them in a pot of food colouring and water? This easy colour-changing flower science experiment is great for learning about transpiration and transport in plants.

Easy Transpiration Experiment

How to make colour-changing flowers

You'll need

White flowers

Food colouring - we've found Wilton gel colours work well. Natural food colourings DO NOT work in our experience.

Water

Small jar or vase

Transpiration experiment - instructions

Trim the flowers at the stalks.

Fill a vase or jar with water and add a little food colouring.

Place the flowers in the jar and leave for a few hours.

Usually, you will see the flowers change colour within a few hours.

Free Transpiration Experiment Instructions

Extra Transpiration Challenges

Try carefully splitting a stem in half with a sharp knife ( ask an adult to do this )

Place one half of the stem in one colour of water and the other in a different colour. After a few hours, you should have a flower with two different-coloured petals!

What is Transpiration?

The white petals change colour because of something called the transpiration stream. Transpiration is the movement of water up the stem of a plant from root to leaf when water is lost from the plant due to evaporation and diffusion of water from a plant's surface. Firstly, water is absorbed by the root and moves through root hair cells via the process of osmosis. It then moves into the xylem vessel, which is the tube that carries the water up the stem. Water moves up the xylem vessel by adhesion (being attracted to the side of the vessel) and cohesion (water molecules being attracted to each other).

When water evaporates from the surface of the leaves, the pressure change pulls the column of water upwards to replace the water lost. Thus, there is a constant transpiration stream through the plant.

The best way to consider this is to imagine you have a thick milkshake - the straw can't carry the milkshake up itself, but if you suck from the top, the milkshake is sucked up the straw. It moves in a column because water molecules are attracted to each other.

What affects the speed of transpiration?

The rate of transpiration is affected by environmental factors

Factors affecting transpiration

Light

Transpiration is faster when there's more sunlight. Stomata ( tiny pores on the surface of a plant ) close when it's dark, as they don't need to be open when photosynthesis is not happening. Photosynthesis also needs sunlight. When the stomata are closed, water cannot escape from the plant's surface.

Temperature

Transpiration happens at a faster rate in higher temperatures. In warm weather, water particles evaporate and diffuse through the stomata faster, increasing the transpiration rate.

Air movement around the plant

When airflow around a plant is good, transpiration is faster as the water vapour that has just diffused and evaporated from the leaf is moved away, increasing the concentration gradient between the air and the inside of the leaf. Diffusion is faster when the concentration gradient is more significant.

The effect of increasing airflow on the rate of transpiration can be demonstrated using celery, food colouring, water and a hair dryer!

What food colouring should I use?

We have found that natural food colours don't work, but these Wilton gel colours work every time.

If you liked this experiment, don't forget to try my other plant science experiments.

Contains Affiliate Links

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Find out how to dissect flowers and learn about their structure with this simple hands-on dissection activity and other exciting plant experiments for kids. Dissecting a flower is a great way to visually show the different parts of a flower, which can be hard to picture from a diagram in a book.

What you need to dissect a flower

Any flowers with large parts work well, for example:

• Lily
• Iris
• Daffodil
• Tulip

Paper plates or sheets of cardboard

Magnifying glass – optional

Tweezers

Scissors

How to dissect a flower

Lay a flower out over a paper plate, tray or sheet of cardboard. Try to identify the different parts.

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

Try to find the following flower parts:

Root - carries water and nutrients from the soil to the plant and keeps it anchored in the ground.

Petal - often brightly coloured to attract insects.

Leaf - uses energy from sunlight for photosynthesis, creating oxygen and sugars for the plant to use for energy.

Pollen is a fine powdery substance containing male reproductive cells. The anthers of seed-bearing plants produce pollen.

Stem - a plant stem transports water and nutrients from the soil to the rest of the plant. The stem supports the leaves and flowers, allowing them to be raised above the ground to be in the light.

Flower Dissection Challenge

Try to find a stigma, anther, ovule, and ovary. A lily is a good flower for identifying these parts.

What is pollination?

Pollination is when pollen from the anthers ( male part ) of one plant lands on the stigma (female part ) of a plant of the same type. The stigma is sticky so that the pollen can attach to it easily.

Pollen can be carried by wind or insects. Once it has landed on the stigma of a plant, it travels down a tube where it fertilises the ovules, which then become seeds.

What is Fertilisation?

Fertilisation is when the male cells from the pollen connect with female cells from the ovules.

What is germination?

Germination is when a seed starts to sprout and grow. One way to demonstrate this is to grow a bean in a jar to discover the conditions needed for a seed to germinate.

Which are the best flowers to dissect?

Anything with large parts works well. Lilies are great, but watch out for pollen stains. Tulips, daffodils, and iris flowers also work well.

More Plant Science Experiments

Find out why leaves change colour in Autumn.

Build a plant growth model from LEGO.

Learn about transpiration using white flowers and food colouring. The colour of the petals will change as the food colouring is transported up the stem and into the petals.

Try growing new plants from tissue cuttings.

Have a go at growing a multi coloured cress caterpillar. Can you guess how we made the leaves different colours?

Create a 3D model of a flower showing the different parts.

Learn about transport in plants with a capillary action science activity.

Can you think of any more plant experiments for us?

Suitable for Key Stage 1 Science

Plants

Identify and describe the basic structure of a variety of common flowering plants, including trees.

Observe and describe how seeds and bulbs grow into mature plants

Find out and describe how plants need water, light and a suitable temperature to grow and stay healthy

Key Stage 2 Science

Identify and describe the functions of different parts of flowering plants

The post Dissect a Flower - STEM Challenge appeared first on Science Experiments for Kids.

Helicopter seeds are a type of seed that spin as they fall from a tree. The spinning movement and the fact that they are light and can catch the wind allows them to travel further from the parent tree than if they just dropped to the floor.

This is one method of seed dispersal used by plants and trees to reduce the amount of competition around the parent plant for light, water and nutrients.

This activity uses simple paper spinners to demonstrate how helicopter seeds fall from a tree.

Which trees have helicopter seeds?

Ash Trees - these helicopter seeds have one wing and hang in bunches from the tree.

Norway Maple

Sycamore - symmetrical wings in a V shape

Make your own seed helicopter

You'll recognise these as simple paper spinners from a previous science activity, but they work really well for demonstrating this kind of seed dispersal.

You'll need

Paper

Paper clip or hair clip

Scissors

How to make a helicopter spinner

Cut out a rectangle from paper like the image below using scissors. Any size works well.

Cut down the dotted lines and attach the two ends together with a paper clip.

Hold the spinner as high as you can and drop.

Watch as the helicopter spins to the ground just like a seed.

Investigation ideas

Try dropping different-sized helicopters from the same point and measure how far they travel from the drop point.

Drop the helicopters inside and outside. Design an investigation to find out If the wind makes a difference to how far they travel.

Add extra weight to the helicopter and try the investigation again.

Do smaller helicopters spin faster than large helicopters?

Print the experiment instructions

Investigation sheet

Another idea for learning about a different type of seed dispersal is to make a sticky seed pod!

If you need a bit of help identifying different trees, try this Tree Identification app from The Woodland Trust.

I have lots more science experiments for autumn you might like and some autumn STEM challenges too!

The post Flying Helicopter Seeds - science investigation appeared first on Science Experiments for Kids.

You might have already seen our exploding seed pods and flying seed helicopters for learning about different types of seed dispersal.

This activity teaches children about sticky seed pods. The challenge is to make a container for a seed that sticks ( temporarily ) to clothing.

One way plants disperse their seeds is by using an animal as a carrier. This type of seed usually has sticky hooks it can stick to an animal and get carried away from the parent plant.

Humans are also good at dispersing seeds. Have you ever found a seed stuck to your clothing or eaten a fruit with a seed inside and thrown the seed outdoors?

Which plants have sticky seeds?

Burdock plants have sticky seeds that attach easily to animal fur. These remind me of Velcro!

Design a sticky seed pod

The activity involves designing and making a sticky seed pod that will stick to clothing for a few minutes before falling off.

You'll need

Velcro

Double-sided tape

Paper

Small containers

Glue

Pom pom or small seed

Instructions

Gather together your materials and create a design for a sticky seed pod. You can print the sheet below to help.

Draw a design and then try to make the seed pod.

We made a very simple package by wrapping a pom pom in paper like a parcel and then attaching double-sided tape to one side.

Test to see if it sticks to your clothes.

Does it stay attached if you jump, run or stretch?

More challenges

Test your stick seed pod on different materials such as cotton, wool, paper, card and foil.

What do you notice about the materials your pod sticks to most easily?

Find out how dandelion seeds fly on the wind.

If you struggle to tell trees apart, this tree ID sheet from The Woodland Trust is super helpful!

The post Sticky Seeds - a seed dispersal investigation appeared first on Science Experiments for Kids.

Ammonites were sea creatures that lived before and at the same time as dinosaurs. They were a bit like a modern-day squid or octopus with a shell. Ammonite fossils have been found all over the world. The fossils resemble a curled-up snake, and for a while, people thought they were remains of snakes, earning them the nickname snakestones!

Ammonites made extra chambers in their shell as they grew, which gave the shell a distinct spiral shape.

How did ammonites swim?

The hollow inner chambers of an ammonite's shell helped them float and control their buoyancy. Ammonites had a siphuncle system which allowed them to diffuse gas in and out of the empty shell to change their buoyancy. Only the outermost chamber housed the soft body.

They squirted water to push themselves along. Modern cephalopods ( octopus, squid, cuttlefish and nautilus ) use this same jet propulsion method to move.

When did ammonites live?

It's thought that ammonites first appeared around 400 million years ago and became extinct about 66 million years ago during the same extinction event that killed non-avian dinosaurs and many other species of animals and plants on Earth.

What did ammonites eat?

Ammonites are thought to have eaten plankton and small crustaceans and were eaten by dinosaurs such as mosasaurus, ichthyosaurus and plesiosaurus.

Ammonite fossils

Ammonites were hugely abundant in the ocean for a very long time, so fossils are plentiful. Scientists use the number and type of ammonite fossils found in a particular layer of rock to date other fossils in the same layer. They are known as index fossils.

Ammonite fossils are found in marine sedimentary rock. If you're in the UK, Lyme Regis in Dorset is a good place to go ammonite hunting.

Ammonite Investigation

How did ammonites control their buoyancy?

The soft body of an ammonite only lived in the outermost section of its shell. The other chambers were sealed off as the ammonite grew and used to control its buoyancy.

Ammonites had a siphuncle system which allowed them to diffuse gas in and out of the empty shell to change their buoyancy. The siphuncle also pumped water out of empty chambers as the body grew.

We can demonstrate how changing the density of the ammonite shell would have changed its buoyancy with a simple demonstration.

You'll need

A jar or a large bottle

Small test tube with a bung or air-tight lid

Buttons, plasticine or another small object

Water

Instructions

Fill the jar or bottle almost to the top with water. The jar needs to be deep enough for the test tube to be completely covered with water when submerged.

Place the empty test tube with the lid on into the jar. It should float on the surface of the water. The test tube represents an ammonite.

Add buttons or plasticine to the test tube until it just starts to dip under the surface of the water.

Add a little bit of water to the test tube containing buttons and watch what happens. You should find the position of the test tube in the water changes the more water you add.

Keep adding more water to the test tube until it sinks to the bottom.

By adding water, you are changing the density of the test tube. When the density of the test tube is greater than the density of the water it is placed in, the test tube will sink.

When water is added to the test tube, its whole density changes, which means its position in the water changes. This is how ammonites control their buoyancy. The siphuncle pumped water out of the newly empty shell chambers and gases in to allow the ammonites to float at the level they wanted.

More about ammonites

Find out how x-rays revealed what ammonites ate.

Read about the inspirational Mary Anning and make a clay ammonite.

The post All About Ammonites appeared first on Science Experiments for Kids.

Easter is just around the corner, so I've put together a collection of egg experiments perfect for this time of year. Eggs are great for experiments as they are inexpensive, easily available and very versatile. We try not to waste food at Science Sparks, but for most of these ideas, you can still eat the actual egg. However, be careful if you have a child with allergies.

Don't forget to check out my ever-growing selection of printable science experiments too!

Egg Experiments for Kids

Egg Drop Experiment

My Humpty Dumpty themed egg drop experiment is great fun. We used sealable sandwich bags filled with different materials to put the egg inside, but another way to do it is to make a parachute or create a container for the egg and drop that.

Unbreakable Egg Experiment

Find out how to make an unbreakable egg. All you need is an egg, and some cling film. We're sure you'll be surprised at how strong an egg actually is!

Egg Experiments with Vinegar

Find out how to make an egg shell disappear! This is like magic! Watch the shell disappear before your eyes. Just be careful not to break the membrane like we did.

Once you've dissolved the shell with vinegar, you can make the egg bounce! Be warned, it might break!

How to shrink an egg

Make an egg shrink and then expand, but first, you'll have to remove the shell to expose the delicate membrane. This is a brilliant visual way to learn about osmosis!

How strong is an eggshell?

Do you think an eggshell is strong or weak? This activity uses eggshells to make a bridge that books can be piled on top of. The shells might be stronger than you think!

Egg in a Bottle

Find out how to force an egg into a small bottle or jar. Watch as the egg drops into the jar like magic. This clever activity works because of differences in air pressure.

Meringue Experiments

Find out what happens when you whisk egg white and why. This one is a bit messy but lots of fun and very yummy!

Once you've perfected your meringue skills, have a go at making a Baked Alaska. This clever dessert allows you to put ice cream in the oven without it melting.

The image below is taken from Snackable Science

Make an Egg Float

Do you know how to make an egg float and we don't mean by letting it go bad!

Eggs as Teeth

Did you know eggs are great for learning about teeth as the shell is made from a similar material? Try soaking eggs in vinegar, coffee or tea to discover what happens.

Egg Vehicles

Create a vehicle to protect an egg in a collision. You could use LEGO, K'Nex or any other materials you like.

Egg Experiments eBook

My new egg experiments eBook contains five brilliant egg investigations that are easy to follow and also great fun.

More egg experiments

Find out how to tell if an egg is boiled or not by spinning it.

Can you think of any more Egg Experiments for us?

If you've got an egg decorating competition coming up, these easy decorated eggs might be helpful, too!

The post Awesome Egg Experiments for Kids appeared first on Science Experiments for Kids.

Here at Science Sparks, we try to make science as easy and accessible as possible. When I ask people why they don't do more science at home with children, one of the answers is usually that science experiments are messy. While this can most definitely be true, there are also lots of non-messy science investigations and experiments around. One of the easiest ways to reduce mess is to try a science experiment in a jar! The jar or glass keeps most of the mess in one place, and the activity can generally be poured away afterwards.

I've pulled together a list of our favourite science experiments in a jar to make science at home even more accessible! Most of these also work with a tall glass if you don't have a jar.

Make fireworks in a jar, grow a bean in a jar, practice estimating, make a DIY barometer and lots more. Which will you try first?

Science Experiments in a Jar

1. Fireworks in a jar

This lovely, colourful science experiment is super easy to set up and carry out but looks fantastic! Watch as swirls of food colouring burst through the oil into the water.

2. Lift an ice cube with a string

Use salt to lift an ice cube out of a jar or glass with a piece of string! Salt lowers the freezing point of water, so the ice melts a little and then refreezes around the string.

3. Dancing raisins

Use baking soda to make raisins dance around a glass of water!

4. Make butter from cream

You'll need some strong arm muscles for this one! Shake a jar of cream for about five minutes, and it will turn into butter! This is a good activity for learning about emulsions and colloids.

5. Floating eggs

Discover how adding salt to water affects its density with this simple science demonstration using an egg!

6. Tooth decay experiment

Soak eggs in vinegar and water for two days to see what happens! This is a great way to demonstrate how acidic food affects tooth enamel.

7. Pumping heart model

This pumping heart model is a great demonstration of one chamber of the heart and valve. It's also something you can keep and use over and over again!

8. Tornado in a jar

Learn all about tornados ( also known as twisters, cyclones or funnels ) with this simple tornado in a jar demonstration.

9. Make a barometer

Learn about air pressure and how it impacts weather with this simple homemade barometer made from a small jar, balloon and a wooden stick.

10. Easy density jar

This density jar is a brilliant way to demonstrate the concept of density to children. The most dense liquids are at the bottom and the least dense at the top. As an extension challenge, children can try to find different small objects to float on each layer.

11. Salt lava lamp

This simple salt lava lamp is a fun twist on the more traditional homemade lava lamp that uses a fizzy tablet. Although the salt lava lamp doesn't look quite as good and isn't as reusable, it is still a lovely science activity for learning about density.

12. Oil and water lava lamp

Homemade lava lamps are one of our favourite science experiments. They are super simple to make, can be used over and over again, and allow you to be as creative as you like. Just drop an effervescent tablet in and watch the fizz!

13. Bean in a jar

Grow a bean in a jar with just a little water. This is a great science activity for learning about germination and the environmental factors needed to make it happen.

14. Rain cloud in a jar

Find out why and how rain falls with this fun and visually appealing rain cloud in a jar.

15. Estimating jars

These aren't a science experiment as such, but being able to estimate is a handy scientific skill. Fill a jar with small seasonal items and ask kids to estimate how many of each are in the jar!

More science in a jar

Mombrite has a fantastic snowstorm in a jar activity.

Fun a Day has some beautiful butterfly sensory bottles that would work perfectly with small jars.

Can you think of any more science experiments you can do in a jar? I'd love you to share in the comments if you've got an idea I can add.

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Creating a 3D neurone ( or neuron ) model is a great way to learn about the central nervous system and how messages are transmitted around the body.

3D neurone models are also a fantastic addition to a school science fair project about the nervous system.

What are neurones?

Neurones ( often called nerve cells ) are specialised cells found all over the body. They carry electrical signals.

Neurones are often very long to speed up nerve impulses. Connections between neurones, although fast, slow the impulse down, so one long neurone transmits a message faster than lots of smaller ones.

What is the central nervous system?

The central nervous system consists of the brain and spinal cord, and the peripheral nervous system is all the nerve cells that carry information to and from the central nervous system.

Neurones are part of the nervous system. Humans have five sense organs ( eyes, ears, nose, tongue and skin ). These contain nerves which send messages to the brain about whatever stimuli they detect. The brain then decides on a response that it sends via more nerve cells to the part of the body that needs to respond.

What are receptor cells?

Receptor cells are specialised cells in the sense organs, and effectors are the part of the body that responds to a stimulus, such as muscle cells.

Information flow from receptors to effectors

Stimulus - Receptor - Sensory neurone - CNS - Motor neurone - Effector - Response

As you can see, there are several different types of neurones, including sensory neurones, motor neurones and relay neurones. Each has a slightly different structure.

Neuron structure

Neurones have a cell body with a nucleus, cytoplasm and other sub-cellular structures.

Unlike other cells, neurones have extensions that connect to other neurones.

Dendrites and dendrons carry impulses towards the cell body. They pick up impulses from other neurones.

Axons carry impulses away from the cell body to other neurones.

Neuron Models

Pipe cleaner neurone model

The neurone model below is made from pipe cleaners, cotton wool and small pom poms.

The pom poms represent the myelin sheath found around some axons. The myelin acts as an insulator to speed up the electrical impulse.

Play dough neurone model

This is a straightforward neurone model made using play dough.

Other ideas for neurone models are to use sweets, modroc or beads!

What is reaction time?

Reaction time is the time it takes you to respond to a stimulus. One easy way to measure reaction time is using a ruler!

What is a reflex arc?

A reflex action is an automatic, very fast response to stimuli. For example, if you touch something very hot or sharp, your reflex action is to move your hand away. A reflex response is faster than a normal response as it requires less thought processing. The impulses travel via the spine or unconscious part of the brain, and the conscious part of the brain is bypassed to save time.

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Human teeth allow us to tear, grind, and crush food into smaller pieces, which we then swallow and digest for energy.

Did you know the way your teeth are aligned in your mouth is unique to you? A bit like a fingerprint.

Parts of a Tooth

Enamel

Enamel is the outer layer of the tooth and the hardest tissue in the human body. Enamel protects the inside of the tooth. It may be tough, but enamel cannot fix itself if it becomes damaged, which is why it's so important to keep teeth clean.

Dentin

Dentin supports the enamel and protects the pulp underneath. It's softer than enamel.

Pulp

This is the middle part of the tooth and contains nerves, connective tissue and blood vessels.

Cementum

Cementum helps the root of the tooth attach to the gums.

Blood Vessels

Blood vessels supply blood to the teeth.

Nerve

Nerves send signals to the brain if something is wrong with the tooth.

Root

The root of a tooth is the part you can't see as it sits inside the gum line. The root is about two-thirds of the whole size of the tooth.

How many teeth do children have?

Children have 20 teeth, and adults have 32.

How many types of teeth do humans have?

Humans have five different types of teeth, each with a different function.

Incisors are the four front teeth. Incisors have sharp, flat edges and are usually the first to bite into food.

Canines are on either side of the incisors. They have sharp ends that help cut and rip food.

Premolars are behind the canines. There are four on the top and four on the bottom. Premolars are bigger than canines and incisors with ridges on the top. This type of tooth is important for grinding food into smaller pieces.

Molars are the two teeth behind the premolars. There are four on the top and four on the bottom; these are bigger than premolars and also help with grinding food.

Wisdom teeth are behind the molars and don't have a specific function.

More teeth activities for kids!

Learn more about the human digestive system by making a model using tights as the small intestine.

Use eggs to learn about tooth decay and find out how to keep teeth healthy and stain free.

Hello Wonderful has a gorgeous tooth anatomy printable.

Make a model of some unhealthy teeth using biscuits and marshmallows. You can find this activity in Gross Science.

The post What are teeth made of? appeared first on Science Experiments for Kids.

I'm always on the look out for new science activities to use with my own children or to recommend to schools. There are lots of great science resources around but it's not often I come across a whole FREE and unique education programme. Dreamachine fuses the arts and science with fascinating investigations about the extraordinary power of the human mind, amazing brains and questions about our sense of self, how we see the world and how we connect with others.  

The activities are aimed at 5-13 year olds and also include free CPD resources and videos for teachers created with the Chartered College of Teaching and Education Support. The Dreamachine lesson plans cover PSHE, Science, and Global Citizenship and are linked to curricula across England, Scotland, Wales and Northern Ireland.

We've had great fun trying some of the activities this week and learned a huge amount while working together.

The resources are all very thorough and include fun facts, background information, examples of questions and extension activity ideas too. It couldn't be easier.

Create a Connectome

The Amazing Brain section is one of my favourite resources from the Dreamachine website. The first activity involves a class of students throwing a ball of string to each other but keeping hold of one end as they throw so a visible network of string connections is made. This is a wonderful way to illustrate the connections the brain makes.

We used a handy template provided in the Dreamachine resources to draw a Connectome.

First we used simple pencil lines to make connections on the printed brain image provided in the pack. Then we experimented by drawing two lines from one dot and then matching colours of connections to dots.

You can see how quickly the connections build up in the brain and how the connection possibilities are endless! The Connectome was a great way to illustrate how everyone's brain is different.

Fun Brain Facts

Did you know that if you counted one neuron of the brain every second it would take around 2700 years to finish counting?

There are approximately 86 billion neurons in a human brain!

Did you know signals transmitted by neurons can travel at up to 300 miles per hour?

Make a Model Neuron

We were so fascinated by the power of the brain that we decided to make a model neuron using play dough.

Neurons are a specialised cell ( other examples of specialised cells are muscle cells, red blood cells and sperm and egg cells ). Messages are sent along the axon via electrical signals which travel from one end of a neuron to another. Information from the eyes and other senses is sent to the brain via neurons. The brain processes the information and decides what to do next.

You can test your reaction time using just a ruler. Can you improve your time with practice?

Head to the Dreamachine website to find the full Amazing Brain pack and lots more science activities about perception, illusions and the power of the brain!

The brilliant Dreamachine schools and families programme has been produced by Collective Act with A New Direction, and in partnership with the British Science Association, UNICEF UK and We The Curious. The Dreamachine project is touring the UK this year as part of the Unboxed: Creativity in the UK programme. 

Find out more > schools.dreamachine.world/

This post was created in collaboration with Dreamachine

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If you decided to visit Antarctica, you'd struggle to survive without specialist clothing and equipment. However, penguins manage to live there perfectly well as they have adapted to survive in their harsh environment. Animals and plants have special adaptations to allow them to thrive in their natural environment.

Animals need food, water, shelter and a safe place to have their offspring to survive. Over thousands of years, they adapt and change to live successfully in their habitat. Species of the same animal can even be adapted to live in different parts of the world. African elephants have bigger ears than Asian elephants as ears are used to cool the elephant down, and African elephants live in a hotter part of the world.

Adaptations can be how an animal looks; some animals are camouflaged to look just like their environment. Some animals have adapted to scare away predators, and others have adapted to be superhunters. Animals all over the world have developed unique adaptations for survival in their specific habitat.

I've compiled a list of 10 amazing animal adaptations demonstrating just a little of the diversity of animal life on our planet.

Once you've read through the list, design your own uniquely adapted animal by combining different animal adaptations. There's a handy printable template at the bottom of this post.

10 Awesome Animal Adaptations

Pufferfish - an amazing ability to puff up

The pufferfish is not a fish to cross. Pufferfish have stomachs that have evolved to be super stretchy, allowing them to inflate with water to scare predators away.

Pufferfish also contain a deadly toxin, making them highly dangerous if eaten!

Elephants - big ears to cool down

Elephants are big animals that mostly live in hot places. They can't sweat like humans, so they use their cleverly adapted ears to cool down. Elephant ears are thin with lots of tiny blood vessels called capillaries. When an elephant gets too hot, blood flows to the ears, where it loses heat, cooling the elephant down.

Elephant ears can also flap to act like giant fans.

African elephants usually have bigger ears than Asian elephants, who live in cooler climates.

Giraffe - very long neck

The long neck of a giraffe gives them a couple of unique advantages over other animals. They can reach food that's REALLY high up and can see enemies from far away.

However, the downside of such a long neck is that it's VERY hard for giraffes to drink water from the ground.

Hummingbird - super fast wings

Hummingbirds flap their wings so fast it's a blur to the human eye. This very clever adaptation means they are the only bird that can fly backwards ( handy for avoiding predators ) and can hover for a long time!

Platypus - electric field detecting bill

The Platypus is a unique species that appears to be a blend of several animals you're probably familiar with. It has webbed feet and a bill like a duck, a tail like a beaver and fur like an otter! Don't be fooled by its cuteness, though, as males have a venomous spur near their back leg!

One interesting adaptation of the Platypus is that its special bill can detect electric fields generated by other animals, which helps it hunt for food.

This is called electrolocation.

Stick Insects - super camouflage

Stick insects have a camouflage superpower! They usually look like either sticks or leaves and can hide remarkably well in their natural environment.

Naked Mole Rats - interesting incisors

Naked Mole Rats live underground. They can't see or hear very well but have special long incisors that can move independently of each other and very strong jaws. This unique adaptation allows them to tunnel underground for miles!

Camel - extra long eyelashes

If you were to walk through the desert, you'd probably have a bit of trouble with sand getting into your eyes and nose.

Camels have adapted perfectly for this scenario and have extra long eyelashes to help prevent sand, dust and other particles from getting into their eyes.

Camels can also close their nostrils to stop sand from getting in their nose and, of course, have one more very special feature, a hump!

Camels store fat in their hump to use for energy when times get tough and food is scarce!

Eagle - super sharp vision

Eagles have some of the sharpest vision of all animals. They have very large eyes for their skull size and a lot more cells on the back of the eye than humans, allowing them to see more clearly and at greater distances.

Eagles also have a 340-degree field of vision compared to the 180 degrees a human has.

However, eagles are not famous for their night vision. Eyes like an owl or a cat are better for seeing a night!

Shark - super smell

Sharks have the most incredible sense of smell. They can detect even very small traces of blood several miles away! Sharks can even tell which direction the smell is coming from, making them extreme hunters.

More Animal Adaptations

Stingrays have flat bodies with eyes on the top and a mouth on the bottom. This allows them to keep an eye out for predators while eating!

The fur of a lion blends into its sandy environment, providing some camouflage!

Polar bears have white fur and a thick layer of fat under their skin, allowing them to be camouflaged and stay warm.

Emperor penguins have blubber under their skin like polar bears and thick feathers to help them stay warm in the harsh environment of the Antarctic!

Which animal adaptation is your favourite? Would you like to be able to puff up like a pufferfish, smell your favourite meal from 3 miles away or have super vision?

Now you're an animal adaptation expert, try this simple activity!

Animal Adaptation Activity

This easy animal adaptation activity gives children the chance to design the ultimate animal by combining different adaptations.

I'd love to see this resource in action, so please do share your mix-up animals!

MIXED UP Animals Worksheet

The post 10 Awesome Animal Adaptations appeared first on Science Experiments for Kids.

If you've ever blown a dandelion that's gone to seed, you've probably found that the little parachute-like seeds detach easily and seem quite delicate. However, dandelion seed puff balls are stronger than you think!

A whole dandelion head can be placed in water and removed again, almost completely undamaged!

What happens to a dandelion in water?

Each dandelion seed is attached to a tiny parachute like structure ( called a pappus ) made up of lots of filaments which allow the seed to fly away on the wind. This clever dispersal method clearly works well as dandelions are very abundant.

Is a dandelion waterproof?

The pappus is omniphilic, which means it repels both oil and water. When the tiny hairs of the pappus are submerged in water, they close up, trapping a water droplet inside.

This feature may help dandelions survive in wet conditions.

Dandelion Facts

A special air bubble forms on top of the filaments above the seed to help keep it in the air longer.

The word dandelion means lion's tooth.

Dandelion seeds are produced asexually, so they don't need to be pollinated. This means all dandelions are genetically identical to their parent plant.

Dandelion flowers close up at night.

All parts of the dandelion are edible!

Although they don't need to be pollinated, dandelions are a very popular source of food for pollinating insects such as bees, moths, and butterflies. Their long flowering season makes them especially useful to insects. Next time you do some weeding, think about leaving some dandelions behind!

How does a dandelion clock form?

When the flower reaches a certain age, it starts to dry out, making the petals fall off, which exposes the seed ball. When the wind blows, the seeds are carried away from the parent plant. This is called seed dispersal.

More about seed dispersal

Learn more about seed dispersal methods by making a sticky seed or an exploding seed pod.

This video explains the science of dandelion seed and how it is specially adapted to travel far from the parent plant.

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How many times a day do you yawn? Do you find yourself yawning if someone near you yawns? Do you associate yawning with boredom or tiredness or both?

Humans yawn around 7-10 times a day, although I have already yawned 3 times writing this so perhaps if you think about yawning you yawn more...

Yawning is associated with being tired or waking up. No one really knows why we yawn but it's thought to be linked with regulating brain and body temperature.

Opening the jaw causes an increase in blood flow to the mouth area which is then cooled as extra air rushes in.

Another theory is that yawning allows for a quick increase in oxygen when carbon dioxide has built up.

Why do we yawn when other people yawn?

Again, no one really knows, but it's thought to be linked with empathy. If they need to yawn maybe you do too?

Or it could be a form of social mirroring, just like you smile back at someone when they smile!

Do animals yawn

All vertebrate animals yawn!

This article from National Geographic about a study into lions yawning is really interesting with some great information on why yawning is contagious!

Facts about yawning

The study of yawning is called chasmology!

Some penguins yawn to attract a mate!

Yawning in animals can be a warning signal.

Babies yawn before they are born!

Some studies have shown a relationship between brain size and length of a yawn!

Activities for learning about yawning

Start a diary and record how often you yawn each day. Each time you yawn try to count how long it lasts and the cause.

Yawn around your friends, do they copy you?

The post Why do we yawn? appeared first on Science Experiments for Kids.

You might think butterflies' brightly coloured wings make them stand out to other animals, but the colours are often a defence mechanism to deter predators!

The coloured leaves of butterflies are an adaptation that has evolved over millions of years.

Why are butterflies brightly coloured?

A warning

Bright colours act as a warning to other animals that the butterfly doesn't taste nice or is poisonous.

For protection

Some species are coloured for camouflage, making it hard for predators to spot them. The Indian leaf butterfly has wings that look like leaves.

Some also have eyespots to make other animals think they are bigger than they are.

The owl butterfly has a large eye spot, making the wings look like the face of an owl!

To attract a mate

Butterflies also use their bright colours to attract a mate.

What about caterpillars?

Butterfly larvae are called caterpillars. Like butterflies, some blend into their environment and don't move around much during the day; some are hairy, which makes them unattractive to predators, and some are brightly coloured, which warns predators that they are toxic.

Butterfly Facts

Butterflies and moths have sensors ( called chemoreceptors ) on their feet, allowing them to taste their food.

They have compound eyes.

Butterflies are the only insects that have scaly wings.

The patterns on the wings of a butterfly are symmetrical.

Butterflies have an interesting lifecycle and undergo a process called metamorphosis, where they transform from caterpillars to butterflies.

Butterflies are important pollinators. They transfer pollen between plants as they feed on nectar.

During the chrysalis or pupae stage of its lifecycle, a butterfly is very vulnerable to predators as they can't move or defend themselves. The chrysalis often looks like a leaf or twig, which gives it a little protection.

Butterflies, like all insects, have an exoskeleton.

You can find butterflies all over the world, except Antarctica.

Butterflies are cold blooded, which means they cannot regulate their own body temperature. They are much more active in warm, humid weather than when it's cold. If you've ever visited a zoo with a butterfly house, you probably noticed how warm it was.

Camouflage activities for kids

Place different colours of small sections of string on grass. Which are easiest to see?

Use different materials to create a camouflage outfit for a small soft toy. Try placing it in different areas outdoors to find out where the camouflage works the best.

Fun ideas for learning about butterflies

Do you know what the biggest butterfly in the world is called?

Create an edible butterfly life cycle with my FREE printable activity sheet!

This butterfly identification sheet from the Wildlife Trusts is brilliant!

The post Why are butterflies brightly coloured? appeared first on Science Experiments for Kids.

The food available to animals varies depending on where they live. In habitats where food is limited, animals with features or adaptations that allow them to access food more easily are likely to survive more successfully than those without the advantage. Animals with adaptations that allow them to live longer are more likely to produce offspring to pass their genes on, and therefore, the advantageous adaptation. This process is known as natural selection.

Discover why bird beaks are different shapes with this fun investigation.

Bird Beak Adaptation Activity

Materials

Pegs

Tweezers

Chopsticks

Straws

Pasta

Pretend bugs

Other items that could be used - mini marshmallows, marbles

Bowls

Beak Adaptation Investigations

Use the pegs and different sized tweezers to pick up the pasta, fish and bugs.

Discuss whether some things are easier to pick up than others. For example, can tiny objects be picked up more easily with tweezers or pegs?

Did you know that birds' beaks are shaped according to their diet?

Finches have a strong, cone shaped beak which they use to crack seeds, a bit like our tweezers.

Insect eaters have thin, pointed beaks ( maybe a bit like chopsticks )used to pick insects off leaves.

Hummingbirds have long beaks like straws which allow them to suck nectar from flowers and eat small insects.

Did you know birds that eat fish, have teeth-like structures on the edge of their beak to hold the fish?

Bird Science Extension Ideas

Collect sticks, feathers and leaves to build a nest. Think about what features the nest should have.

Build a bird's nest using just tweezers. Remember, birds only have their beaks to build.

Facts about birds

Long-tailed tits use up to 2,000 feathers in each nest and fly between 600-700 miles to collect the materials needed!

Sparrows take advantages of holes in roofs to build their nest, they stuff the hole with grass saving a lot of time and effort.

Chaffinches nest in forks in trees and use sticky cobwebs to form anchors for the nest’s foundation. 

Some birds, such as owls, use natural holes in trees to keep their young safe. This saves a lot of time and effort building a nest.

See the RSPB website for more information about bird nests and how you can help birds make their homes.

Bird Beak Challenge

Research about Darwin's Finches.

What is selective breeding?

Selective breeding is when an animal or plant with a useful characteristic is used to breed. The offspring with the desirable characteristic are used to breed again, and the same is done with their offspring. Eventually, a new breed is produced where the animals or plants always have the desired characteristic.

Sometimes, two different breeds with different characteristics are bred together to produce a new breed with both characteristics from the original. For example, an apple tree that is naturally resistant to disease could be bred with a tree that grows a lot of apples. The cross-bred tree would be resistant to disease and grow a lot of apples!

Selective breeding is also known as artificial selection.

Science Concepts

Evolution

Natural Selection

Selective breeding

The post Birds, Beaks and Adaptations appeared first on Science Experiments for Kids.

Transpiration is the loss of water from a plant. Transpiration mainly occurs from the leaves. Water vapour diffuses out of the stomata ( tiny pores mostly found on leaves ).

Loss of water from the leaves creates a pull on the water in the xylem cells, drawing water up the plant. This movement of water from roots to leaves is called the transpiration stream.

Xylem cells form a continuous tube from the leaves of a plant to the roots, a bit like a drinking straw providing a continuous flow of water.

The transpiration stream transports minerals and water around the plant and keeps cells turgid ( full of water ) so they can support the plant without it wilting.

Rate of Transpiration Experiment

How does increasing temperature and airflow around a plant affect the transpiration rate?

This simple investigation uses a hairdryer to increase the airflow and temperature around the leaves of a celery stick to find out how the transpiration rate is affected.

You'll need

Two celery stalks with leaves

Food colouring

Water

A hairdryer

Ruler

Instructions

Choose two stalks of celery with leaves that are similar in size.

Cut them to the same length.

Place each stalk in a container of water and food colouring. Make sure the same amount of water and food colouring is used for each sample.

For half an hour, blow warm air from a hairdryer over the leaves of one celery stalk every 5 minutes.

After half an hour, remove the celery stalks from the water and carefully slice them to see how far up the coloured water has reached.

How does increasing airflow and temperature affect the rate of transpiration

We found that the celery sample exposed to heat from the hairdryer had a much faster rate of transpiration than the celery that was not exposed to heat.

The coloured water had travelled much further up the stalk of the sample exposed to heat than the one not.

How the movement of air affects transpiration

Air flow removes water vapour from around a leaf, creating a concentration gradient ( low concentration of water in the air and high concentration in the leaf ) between the leaf and air, increasing water loss from the leaf. If there's not much airflow, the water vapour doesn't move far from the leaf, so there's a high concentration of water inside and outside of the leaf and so no concentration gradient for diffusion.

How temperature affects transpiration

Higher temperatures mean water molecules evaporate at a faster rate which increases the rate of transpiration.

What else affects the rate of transpiration

The amount of light also affects the transpiration rate. Stomata close in the dark so water cannot diffuse out.

More experiments to investigate transpiration

These colourful flowers look much more impressive than the celery, but the process is the same!

Water is transported up the stem of a plant by a process called capillary action. You can try this out by placing paper flowers into a tray of water and watching them open up.

You might also like my 3D model of a flower! This is great for learning about the different parts of a flower.

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Are viruses alive is a tricky question that has caused a some debate over the years.

The general view is that viruses are not alive. They don't respire, convert nutrients into energy or excrete waste products like organisms we class as being alive do. Viruses can't even reproduce without taking over another living cell. Once a virus has infected a host cell, it takes over the machinery of the cell to create more virus!

If we compare viruses to a bacteria, bacteria can reproduce independently outside a host, but viruses cannot survive without a host, and usually can't last long on a surface.

4 reasons a virus is not alive

• Viruses don't have cells like other organisms. They have a very basic structure of RNA or RNA ( genetic material ) protected by a simple protein coat.
• Viruses cannot reproduce without a host cell.
• They don't produce their own energy.
• Viruses don't respond to their environment like other organisms.

However, viruses can replicate ( inside a host cell ) and do evolve, so what do you think? Is a virus both living and non-living? The debate is open...

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Generally the bigger an organism is the smaller its surface area compared to its volume.

Surface area to volume ratio is a really important factor in how well an organism can exchange substances with its environment. A large mammal like a human could never absorb enough oxygen to survive through its skin which is why mammals have lungs. Lungs contain millions of tiny sacs called alveoli which provide a large surface area for gas exchange. In humans the alveoli cover have a surface area of around 100m². Comparatively the surface area of the average adult's skin is only around 2 m²!!

Examples of organisms exchanging substances with their environment

Gas exchange in the lungs

The lungs of humans ( and other mammals ) are where gas exchange occurs. Oxygen is transferred into the blood and carbon dioxide ( the waste product of respiration ) is removed. For this process to be efficient it needs a large surface area. The alveoli ( tiny sac like structures ) provide this.

How are the alveoli specially adapted for gas exchange?

• Huge surface area.
• Thin walls ( so the gases don't have far to travel )
• A moist lining so the gases can dissolve.
• A good blood supply.

Oxygen and carbon dioxide are exchange by a process called diffusion. When blood arrives at the alveoli it is returning to the lungs after transporting oxygen to cells of the body and collecting carbon dioxide to be expelled out from the lungs. The concentration of carbon dioxide in the blood is high ( and low in the alveoli ) and the concentration of oxygen in the alveoli high ( and low in the blood ) so a concentration gradient is maintained for diffusion.

Carbon dioxide diffuses out of the blood into the alveoli.

Oxygen diffuses from the alveoli to the blood.

Villi in the digestive system

The small intestine contains lots of tiny projections called villi. Like the alveoli in the lungs these increase the surface area of the small intestine.

Food that has been broken down into small molecules is absorbed into the blood via the villi.

Plant leaves and photosynthesis

The leaves of plants have a large surface area to volume ratio which allows them to absorb a lot of light for photosynthesis.The thin leaves also allow easy diffusion of carbon dioxide and oxygen in and out of the leaf.

Surface area to volume ratio with sugar cubes

This simple activity demonstrates easily the difference surface area to volume ratio can make.

You'll need

Sugar cubes

3 small trays or plates

Food colouring

Small measuring container

Water

Instructions

Half fill the measuring container and add a little food colouring.

Pour a thin layer of the coloured water onto the each plate. Make sure each has the same amount of water.

Place a single sugar cube onto one plate and time how long it takes for the sugar cube to change colour completely.

Now place 8 sugar cubes ( in the arrangement the sugar cubes labelled 1 ) onto the next plate and time how long they take to become fully saturated.

This time place 8 sugar cubes ( in the arrangement of the sugar cubes labelled 2 ) onto the next plate and time how long they take to become fully saturated.

Surface area and volume ratio calculations

Volume = length x width x height

Surface area = length x width

Single cube

Each side is 1cm long

The surface area of the single cube is: (1x 1) x 6 ( 6 sides ) = 6cm²

Volume is 1 x 1 x 1 = 1 cm²

Surface area to volume ratio is 6 : 1

Sugar Cube Arrangement 1

Volume 2 x 4 x 1 = 8

Surface area

Top and bottom (4 x 2) x 2 = 16

Sides ( 2 x 1 ) x 2 = 4 and

(4 x 1 ) x 2 = 8

Total surface area 28

Surface area to volume ratio = 28:8 simplified to 3.5:1

Sugar Cube arrangement 2

Volume

2 x 2 x 2 = 8cm²

Surface area

( 2 x 2 ) x 6 = 24

Surface area to volume ratio 24 :8 simplified to 3:1

Sugar cube arrangement 1 has a larger surface area compared to its volume, so you should find that this arrangement absorbs water faster than arrangement 2!

Quick Surface Area to Volume Ratio Facts

Some organisms have a specially adapted body shape to increase their surface area to volume ratio. Flatworms have a flattened body to allow substances to pass in and out easily.

Elephants have big ears to increase their surface area to volume ratio which allows them to cool down more effectively as they have a larger surface area over which to lose heat.

The post Sugar Cube Surface Area to Volume Ratio Investigation appeared first on Science Experiments for Kids.

The human body is pretty amazing! We have skin to help protect us from pathogens and pollutants, a skeleton to allow us to move and protect vital organs and a digestive system that can break down food, keeping the good bits and expelling the waste!

These fun human body facts are a great starting point for learning more about the wonders of the human body.

Facts About The Human Body

The skin is the largest organ of the human body.

The skin is part of the integumentary system.

The human body is created from 13 chemical elements.

Eyebrows keep stop sweat dripping into your eyes!

Humans are 65% oxygen ( mostly in the form of water H₂O )

The human brain contains about 100 billion nerve cells.

The texture of your brain is like tofu!

Did you know that taste is linked to smell?

The human brain has two halves. The halves are called hemispheres! The left hemisphere controls the right side of your body and vice versa.

The brain can detect 10,000 different smells!

Nerve signals or impulses travel at 250mph!

Around 90% of people are right handed!

DNA is shaped like a twisted ladder ( double helix )

An adult body has 50-100 trillion cells!

The human heart beats around 100,000 times a day.

A meal takes around 18-30 hours to pass through you.

Identical twins have different fingerprints.

The iris of the eye is as unique as a fingerprint.

Muscles work in pairs so they can pull in different directions.

You sweat about 500ml of liquid each day.

Nails grow fastest in summer.

There are four blood groups and positive and negative varieties of each type. These are A, B, AB and O.

The hardest substance in the body is tooth enamel!

The average person spends ⅓ of their life asleep! That's 4 months out of every year.

There are only three areas of skin that don't grow hair. These are your lips, palms of hands and soles of feet!

If you want to learn more about the human body, try this collection of human body science experiments!

The post Human Body Facts appeared first on Science Experiments for Kids.

Pathogens are organisms that cause disease. Viruses, bacteria, protists and fungi are all pathogens. Pathogens cause communicable diseases.

Diseases can be communicable or non-communicable.

What is a communicable disease?

Communicable diseases spread between people. Non-communicable diseases cannot be spread between people. An example of a non-communicable disease is heart disease.

Examples of viral diseases

• Ebola virus disease is caused by ebola virus. Ebola is a nasty virus with a high death rate. Outbreaks occur sporadically in Africa.

• Influenza ( flu ) caused by the influenza virus.

• Chicken Pox also known as varicella and caused by varicella-zoster virus.

• Covid-19 caused by SARS-CoV-2.

Examples of bacterial diseases

• Cholera is caused by Vibrio cholerae and usually spreads via contaminated water supplies.

• Tuberculosis is caused by Mycobacterium tuberculosis. It spreads through the air when an infected person coughs.

Examples of diseases caused by protists

Protists are microoganisms which have features that belong to animals, plants and fungi.

• Malaria is spread by mosquitoes carrying a protist called Plasmodium. In this instance mosquitoes are called a vector. They spread the disease when they suck blood from an infected person and then suck the blood from an uninfected person.

• African sleeping sickness is caused by a protist called Trypanosoma transmitted by the tsetse fly.

Both the protists that case Malaria and African Sleeping Sickness are pathogenic parasites.

Examples of diseases caused by fungi

• Athletes foot is a common fungal skin infection usually found between the toes.

• Ringworm is another fungal skin infection which causes a ring shaped itchy rash.

Pathogen Match Game

Grab this FREE pathogen match game to reinforce learning about different types of pathogens and the diseases they cause.

Ideas for learning about viruses

These plasticine virus models are a fun way to learn about virus structure.

Find out why hand washing is so important for preventing the spread of diseases.

Ideas for learning about bacteria

Find out how bacteria are different to viruses.

Discover why food rots and the role bacteria play in decomposition.

These plasticine bacteria models are great fun too and a hands-on way to learn about the shapes of different bacteria.

The post What is a pathogen? appeared first on Science Experiments for Kids.

We've heard a lot about viruses recently, but how do they work? Viruses cannot live for long without a host. Viruses consist of either a DNA or RNA genome ( genetic code ) and a protein coat, some also have an extra fatty envelope to protect their genetic material. They cannot reproduce without being inside a living cell.

Once inside a cell, viruses use the machinery of the cell to replicate themselves.

Luckily for us the human body has lots of natural responses to protect us from viruses and other harmful pathogens.

How does a virus enter the body?

The human body has several lines of defence against pathogens including viruses. Physical barriers include the skin and mucous membranes. The non specific immune response involves cells from the immune system attempting to destroy pathogens inside the body. Finally the adaptive immune response occurs when a particular pathogen has invaded the body before. Antibodies specific to the invading pathogen are produced to destroy them.

Defence Number 1 - skin and scabs

The first defence against viruses is the skin. Skin is the largest organ of the human body. It helps regulate body temperature, acts as a barrier against bacteria and viruses and is home to 1000s of receptor cells which allow us to feel something when we touch it.

Viruses enter the body through the nose, mouth, eyes or breaks in the skin. When the skin is damaged scabs form over the break to stop pathogens entering.

Make your own clotting blood

This pretend blood recipe actually clots like real blood forming a scab!

Jelly Skin Model

One way to learn about the skin is to make a model of the different layers.

I made this from jelly, liquorice, small sweets and a soft tortilla wrap.

Defence Number 2 - Snot, sweat and saliva

Sticky snot in the nose helps to filter pollutants and pathogens from the air you breathe, preventing them from reaching the lungs. Snot also warms and moistens air before it reaches the lungs.

The next time you think of snot being a bit gross remember how helpful it is!

Did you know sweat, tears and saliva also act as a barrier against pathogens? These all contain an enzyme called lysozyme which can destroy viruses and bacteria.

Make a snot trap

This snot trap is made from cornflour ( cornstarch ) and water. If you sprinkle a bit of cinnamon ( pretend pathogen ) on top, the "snot" will trap it just like the real thing!

Defence number 3 - earwax and nasal hairs

Ear wax also helps trap dust and pathogens before they reach the delicate inner ear!

Defence Number 4 - ciliated epithelial cells

The trachea ( windpipe ) contains lots of mucus and ciliated epithelial cells which force mucus and trapped pathogens back to to the throat to be coughed out of the body or swallowed also preventing them reaching the lungs.

Defence Number 5 - coughs and sneezes

Coughs and sneezes are the body's way of trying to expel germs from the lungs.

They are also a way pathogens can spread between people. This is why it's good to cough into your hands or elbow to trap the germs. Just don't forget to wash your hands afterwards.

Make a sneeze machine

Try adding a couple of tablespoons of water to a balloon using a funnel. Blow up the balloon, hold it up in the air with the end pointing away from you and let the air out. The water will fly out, just like germs escaping from your body when you sneeze!!

Defence number 6 - stomach acid

Pathogens which reach the stomach have a big difficulty to overcome. Acid!!

The stomach contains gastric acid to help break down the food you eat, stomach acid has a pH of around 2 which kills some ( not all ) pathogens.

The stomach has a special lining to stop it becoming damaged by the acid, but if you vomit the acid can make your oesophagus and throat sore.

This activity demonstrating the path of food through the human digestive system uses orange juice as the stomach acid.

Defence 7 - Inside the body

If a pathogen manages to overcome the defences on the outside of the body the cells of the immune system kick in to destroy them.

White Blood Cells

White blood cells ( leukocytes ) are constrantly travelling around the body in the blood searching for new pathogens to destroy. There are several different types of white blood cells.

Make a blood cocktail

This blood cocktail is a fun and tasty way to demonstrate the what's in blood.

I used soda water for the plasma, pomegrante seeds for red blood cells, banana for white blood cells, and pineapple for platelets.

For every 1 white blood cell there are about 40 platelets and 600 red blood cells which is why the drink is mostly pomegranete!

Lymphocytes

Lymphcytes produce antibodies. Antibodies act in several different ways.

• Bind to pathogens allowing them to be recognised by phagocytes which can destroy them.
• Clump pathogens together so they can be more easily destroyed.
• Neutralise toxins.

There are two types of lymphocytes both are made in the bone marrow.

B lymphocytes find foreign cells and attach to them, while T lymphocytes destroy the invaders found by the B cells.

B cells are the ones that produce antibodies.

Phagocytes

Phagocytes engulf and destroy pathogens by surrounding them in a vacuole and then secreting enzymes to destroy them. This process is called phagocytosis.

What's the difference between phagocytes and lymphocytes?

Lymphocytes mount a specific targeted immune response to pathogens ( adaptive immunity ).

Phagocytes have a more general response and engulf and destroy all pathogens in the same way ( innate immunity ).

If you want to read more about immunology ( we've only scratched the surface here ) there are some great resources on the British Society for Immunology website.

What does it mean if you are immune to a virus?

We say someone is immune to a virus or bacteria when they have antibodies in their blood ready to fight the pathogen as soon as it enters the body. As soon as the immune system recognises the pathogen it creates antibodies to fight it very quickly, so the infected person probably doesn't even realise they were infected!

Immunity can be natural ( after an initial infection ) or acquired ( from a vaccine ).

The post Journey of a virus - how a virus infects the body appeared first on Science Experiments for Kids.

Is taste linked to smell? Have you ever wondered why food doesn't taste as good when you have a cold and blocked nose?

When you eat, smell chemicals from the food travel up your nose, where they are detected by tiny nerve endings at the back of the nose. These nerves send a message to the brain, which becomes part of the overall taste sensation you experience.

If your nose is blocked, the food smell chemicals can't reach the nerve receptors, and so the overall taste is not as strong.

The smell of food can also act as a warning. If you open a carton of milk and it smells sour, you know before tasting it that it won't taste good.

Taste and Smell Investigation

One way to investigate how smell affects taste is to close your eyes, hold your nose and ask a friend to feed you something. This activity works really well with different flavour jelly beans as the texture for each jelly bean flavour is the same, but the taste should be different!

Print the activity and try it for yourself!

Find this and more smelly science experiments in Gross Science!

The post Is taste linked to smell? appeared first on Science Experiments for Kids.

Mitosis is the stage of the cell cycle where the cell divides. Mitosis is used by multicellular organisms to grow or replace damaged cells. This paper plate mitosis activity uses pipe cleaners to show the stages of mitosis.

The key thing to remember about mitosis is that it produces two new daughter cells from one parent cell. Each daughter cell is genetically identical to the parent cell.

Mitosis is different to Meiosis where each new cell is not identical to the parent cell and only has half the number of chromosomes of a normal cell.

Paper Plate Mitosis

We used pipe cleaners and paper plates to demonstrate mitosis in a very basic way!

Interphase

This is when a cell is getting ready to divide. It increases the number of subcellular structures ( mitochondria, ribosomes etc), duplicates its DNA and forms chromosomes.

A chromosome has two arms, the left has the same DNA as the right.

Each arm is called a chromatid.

Mitosis

When a DNA has copied it's contents and DNA it can go through the process of mitosis to divide.

Prophase

Chromosomes condense to become shorter, the membrane around the nucleus breaks down leaving the chromosomes free in the cytoplasm.

Metaphase

Chromsomes line up in the middle of the cell.

Anaphase

Spindle fibres form and pull the chromosomes apart. One chromatid from each chromosome moves to each end of the cell.

Telophase

Membranes form around each set of chromosomes. Each new cell now has it's own nucleus.

Finally the cytoplasm and cell membrane divide to give two separate new cells. This is cytokinesis.

Mitosis - Quick Facts

Mitosis is where one cell divides into two genetically identical cells.

Mitosis occurs mostly for growth and replacement of damaged cells.

Mitosis is part of the cell cycle and usually divided into 5 stages.

More cell biology for kids

Find out about cell structure and function of subcellular structures with my cell models.

Create a DNA model using candy to learn about the double helix structure.

The post Paper Plate Mitosis appeared first on Science Experiments for Kids.

Once a plant has made seeds ( remember pollination and fertilisation? ) they need to be dispersed.

Seed dispersal is the scattering of seeds. If seeds just dropped next to the parent plant, they would be competing for nutrients and light, so it's better if seeds are spread out, allowing them to grow with less competition from other plants.

There are several mechanisms of seed dispersal depending on the plant or tree the seed is from.

Seed Dispersal Mechanisms

Wind dispersal of seeds

Dandelions have parachutes to help them catch the wind.

Sycamore seeds have wings to help them float.

Animal dispersal

Animals are very helpful when it comes to seed dispersal.

Seeds covered in tasty flesh are eaten by animals which poo the seeds out far from the parent plant.

Some trees have sticky seeds which attach to the fur of an animal and fall off as the animal moves around.

Trees such as oak and hazel trees take advantage of the hoarding nature of animals like squirrels. Not all the nuts are eaten; some are left behind to grow into new trees!

Water dispersal

Willow and alder trees often live near a source of water, they drop the seeds into the water which then float away.

Exploding seeds

Peas, lupins and violas spread their seeds by exploding them out of pods! This clever mechanism means the seeds shoot far from the parent plant and doesn't rely on animals or other factors.

Seed Dispersal Activity Sheet

The sheet below can be printed and used for reference or could be cut up and used as a matching activity.

Make an exploding seed pod

Ballistic or explosive seed dispersal is perhaps the most fascinating of seed dispersal mechanisms. The explosive pressure is generated as the seed pods dry out.

A squirting cucumber is one example of a plant which uses this mechanism. Once the fruit of the squirting cucumber matures, it explosively ejects the seeds.

Make your own exploding seed pod

It's not quite the same mechanism, but you can explode pretend seeds from a cup to demonstrate the process of how this mechanism shoots seeds away from the parent plant.

You'll need

A paper cup with the bottom cut off.

A balloon with the end tied and the top removed.

Small pompoms

How to make an exploding seed pod

Attach the balloon to the bottom of the paper cup, like in the image above. If it slips off, try securing it with an elastic band.

Fill the cup with pompoms or other small light items, pull back the balloon end and release.

The pompoms should shoot out like exploding seeds.

Experiment with holding the cup at different angles and using different amounts of pompoms.

How far can you make your seeds spread?

Can you design a different seed explosion device?

More plant science activities

Dissect a flower ( lilies work well ) to learn about the different parts.

The Woodland Trust has lots of advice and tips for identifying different trees.

Royal Baloo has a great playdough seed activity.

Build your own sticky seed pod. This is great for learning about animal dispersal.

Make a 3D model of a flower.

This activity was also used for a Popping Planet investigation in This IS Rocket Science.

The post Exploding Seeds - Create a seed explosion device appeared first on Science Experiments for Kids.

Did you know blood makes up around 7% of the weight of a human body?

The average adult has 5 litres of blood flowing around their body in a massive network of arteries and veins transporting oxygen and nutrients to cells. Blood also removes waste, contains cells that fight infection and helps with temperature regulation.

There are three types of blood vessels, each with a different function

Arteries - carry blood away from the heart. These have thicker, more elastic walls than veins as blood is pumped from the heart at high pressure.

Capillaries - these branch from arteries and carry the blood very close to cells so food and oxygen can be transported into cells and waste products removed. Capillaries have very thin walls, allowing substances to diffuse easily from the blood to cells and vice versa.

Veins - carry blood back to the heart. Veins contain valves to help keep blood flowing in the right direction.

Fun ideas for learning about blood

What is blood?

Blood contains:

red blood cells - carry oxygen around the body

white blood cells - destroy pathogens and make antibodies

platelets - help blood to clot

plasma - a straw coloured liquid that carries everything in the blood, not just red and white blood cells, but also nutrients, waste products, hormones and antibodies.

What's inside blood?

One way to learn about the different components of blood ( and also a fun Halloween activity ) is to make a mini blood bath.

We used red water beads for red blood cells, table tennis balls for white blood cells and white pompoms for platelets. You can clearly see how many red blood cells there are compared to white blood cells and platelets.

Make a tasty blood cocktail

Another slightly less creepy way to learn about blood is to make a blood cocktail.

This activity is taken out of my book GROSS Science Experiments, but includes pomegranate seeds for red blood cells, soda water for plasma and pineapple for red blood cells.

Build a pumping heart model

Blood is pumped around the body by the heart. The heart and blood vessels make up the circulatory system.

This simple pumping heart model shows how the heart works.

Make a Scab

When skin becomes damaged, platelets stick together to form a thick and sticky clot. This becomes what we call a scab. It helps prevent micro-organisms and toxins from getting into the bloodstream.

You can make jelly scabs to learn about this process. The jelly thickens and sets just like a scab!

Pretend blood

Another way to learn about clotting is to make pretend blood. One of these recipes will thicken up, and one won't!

Red Blood Cell Cakes

Red blood cells are shaped like indented flattened disks ( like a doughnut with no hole ) and contain haemoglobin, which transports oxygen around the body.

These red blood cell cupcakes show the unique shape of red blood cells. Every drop of blood contains millions of red blood cells!! The biconcave disc shape gives red blood cells a large surface area for absorbing oxygen.

More blood and heart themed science activities

This blood model in a bottle is great from My Joy Filled Life.

Make a very basic stethoscope to hear a heart beating.

Learn about the inspiring Marie M. Daly and her work on the circulatory system.

Or, try one of my other science activities for learning about the human body.

The post Science activities for learning about blood appeared first on Science Experiments for Kids.

Genes play a large role in how you look and everything else that makes you the person you are!

What is a gene?

Genes are found in chromosomes which are found in the nucleus of cells. Chromosomes are coiled up lengths of DNA each carrying lots of genes.

Remember - chromosomes are made of DNA and genes are short sections of DNA.

How many chromosomes do humans have?

Human cells have 46 chromosomes, which are found in pairs. One chromosome in each pair is inherited from each parent, which means offspring have a combination of both parents' characteristics. This is called inherited variation.

Dominant and recessive genes

Genes can be dominant or recessive. The dominant gene is the one that is shown in an organism's phenotype ( observable characteristics ). For example, brown eye colour is dominant over blue, so if a person has one blue eye gene and one brown eye gene, they will have brown eyes as it is the dominant gene that is expressed. Different versions of the same gene are called alleles.

What is variation

Variation refers to differences between organisms. Some differences are visibly obvious, such as hair and eye colour, while others are not obvious, such as blood type.

Continuous variation refers to variation of things that can have a range of values, such as height and weight.

Discontinuous variation is where characteristics can only have a certain value. For example, blood group and eye colour.

What about the environment?

The environment also plays a role in how a person looks, how healthy they are, and other factors. For example, if a person has genes that make them athletic, they wouldn't reach their full potential if they were undernourished or lived in an area with high levels of air pollution. Almost all characteristics are affected by both genetic and environmental factors.

Genes are not just for humans

Plants inherit characteristics from the parent plant via genes, too. They are also affected by environmental factors. For example, a plant with genes to grow tall won't grow well in the dark or in poor soil, even with genes that predispose it to height.

What does DNA look like?

DNA is made up of two long strands joined together to form a ladder like structure which is then twisted into a spiral. The long strands ( or backbone ) of DNA are made from phosphates and sugars and the rungs of the ladder are made from nucleotide bases linked together by hydrogen bonds.

Our candy DNA model is a good activity for learning about the structure of DNA.

What are base pairs?

DNA contains nucleotides. There are four different nucleotides:

Adenine

Thymine

Cytosine

Guanine

We call these bases and usually refer to them by the first letter of their name.

A pairs with T and G with C.

The order of the bases forms a code that cells use to make proteins.

One way to illustrate this is to thread different beads on pipe cleaners to show that the two sets of pairs always pair together.

More activities for learning about DNA and genes

Read about Rosalind Franklin and the role she played in discovering the double helix structure of DNA.

Learn about how cells divide with a paper plate mitosis model.

The post What is a gene? Genes and variation appeared first on Science Experiments for Kids.

Magic opening flowers are a brilliant, super simple science investigation using just paper and water. The folded paper flowers open up as the paper absorbs the water. They are a great way to learn about capillary action and transport of water in plants too.

You can make these as simple or creative as you like. Try experimenting with different flower shapes, types of paper and sizes of flowers. This investigation is great for preschoolers who will love to watch the flowers open to reveal a drawing inside. Older children can use it as part of a plant science unit or use it to practice correct experimental procedures.

If you like this activity, you'll love my other paper science experiments!

You'll need

Tray

Water

Paper – sugar paper works best

Other types of paper to experiment with

Scissors

Waterproof pens - optional

Magic opening flowers instructions

Half fill the tray with water.

Cut out several differently shaped flowers from different types of paper.

Fold the petals up.

Draw a little image inside - optional

Carefully place the flowers on the water and watch as they open up.

If you don't want to cut out your own flowers, try my template.

Make it an investigation

Place flowers made with different types of paper onto the surface of the water at the same time. Record how long each takes to open up.

Remember to make this a fair test, the flowers must be the same size and placed in the water at the same time.

What's happening?

Paper is made from lots of fibres. As they absorb water, they swell, the paper expands, and the flower opens up.

More Science for Kids

Mombrite has a great capillary action experiment using celery.

Make slushy drinks, ice excavations, create a mini water cycle and lots more water science experiments.

I also have an exciting collection of magic science tricks you might like too!

The post Magic Opening Flowers appeared first on Science Experiments for Kids.

Did you know that honey bees dance to share information with the rest of their colony? Bees use different types of dances to let other bees know where to find nectar ( their food source ).

What is a waggle dance?

Bees dance in a figure of eight and wag their tail in the middle of the movement. The further away the food source is, the more waggles there are in the dance. The direction of movement and orientation of the figure eight also give information to other bees.

The faster the bee dances, the closer the nectar!

Round dance

The round dance ( when bees dance in a circle ) means nectar is close by.

Shiver dance

Bees dance like they are shivering to tell other bees about a good location for a nest.

Create your own waggle dance

Design your own waggle dance using different movements to tell a friend whether food ( or an object ) is close or far away.

Can your friend understand the instructions?

Extension task

Find a way to communicate other things, such as the weather or hazards that may be encountered on a journey.

Bee Facts for Kids

Did you know honeybees steal honey from other hives?

A queen honeybee can live for up to FIVE years.

Honeybees have a separate stomach just for nectar, which is then transferred to the honey-making bees in the hive! The other stomach holds the nectar the bees use for food.

The queen bee is usually the mother of ALL the bees in the hive.

Female honeybees have little sacs on their legs for carrying pollen.

Honeybees visit 2 million flowers to make 500g of honey!

Bees have FIVE eyes! Two compound eyes and three smaller eyes called ocelli.

Bees suck nectar through a long tube called a proboscis.

A male bee is called a drone. These only live for a few weeks and don't have stingers. They also don't collect nectar or pollen.

Did you know bees are in danger from climate change and human activities? Find out how you can help save the bees with my fun bee worksheets!

The post Do the Waggle Dance - Bee Facts for Kids appeared first on Science Experiments for Kids.

Our changing climate and loss of bee friendly habitats are not good news for bees or the planet. Some species are already extinct, and many more are on the threatened list, but why are bees so important?

Why do we need bees?

Bees pollinate flowers

Bees pollinate 75-80% of food crops worldwide. Without bees to spread pollen between flowers, plants wouldn't be able to reproduce, and there would suddenly be a lot fewer plants in the world.

Without pollination, plants can't reproduce

Fewer plants mean less food, clothing and even medicines!

Plants are useful for lots of reasons

Plants also absorb carbon dioxide from the environment and produce oxygen ( by a process called photosynthesis ). Humans and animals need oxygen to breathe, and plants play a vital role in reducing carbon dioxide levels in the air.

Animals eat plants

Plants are an important food source for many animals, not just humans. If plant populations decline, the ripple effect will spread up the food chain.

What can we do to save bees?

Build a bug hotel

Building a bee or bug hotel will attract bees to your garden and give them a safe place to live.

If you have a lot of space, this pallet bug hotel is amazing! Old pallets are ideal for constructing a large bug hotel. Carefully stack them on top of each other and fill them with natural materials that provide bugs with numerous hiding places. Remember to leave enough space for bugs to move around, but not so much that bigger animals like hedgehogs can get in.

Make sure to add a roof to keep the bugs dry, and if you want to make it extra welcoming to little critters, plant some insect-friendly wildflowers close by!

Be more natural

Reducing the number of chemicals you use in the garden is another easy way to help save the bee population. Search for natural solutions to pests rather than reaching for pesticides. The RSPB has some great natural ideas for getting rid of pests!

We've had some success with copper tape stopping slugs from reaching our plants.

Create a bee-friendly garden

Creating a bee-friendly garden is another way to help. Bees need a supply of nectar and pollen from early spring to late autumn, so planting lovely flowering plants is very helpful to the bee population. Bees also need water, so a shallow dish of water and some flat stones to land on are a good addition to a bee garden, too.

If you need more ideas, Friends of the Earth has lots of suggestions for how to be more bee-friendly.

Record your ideas for saving the bees on one of my FREE worksheets!

The post Why do we need bees? appeared first on Science Experiments for Kids.

Diffusion is the movement of a substance from an area of high concentration to an area of low concentration until its concentration becomes equal throughout the available space.

This video shows diffusion in action.

Diffusion Demonstration with Squash and Water

Food colouring or juice in water is a great demonstration of diffusion. You can see the food colouring starts in one area and then starts to spread from areas of high food colouring concentration to areas of low food colouring concentration. Eventually, the food colouring spreads throughout the whole glass and the colour becomes paler and even throughout. ​

I used food colouring in the images below to make the process easier to see.

Diffusion using food colouring and water

​

What is diffusion?

Diffusion is the movement of a substance from an area of high concentration to an area of low concentration.

Diffusion occurs in gases and liquids. Particles in gases and liquids move around randomly, often colliding with each other or whatever container they are in. When they collide, they change direction, which means eventually they spread out through the whole available space.

Examples of Diffusion

Diffusion in humans

Oxygen diffuses from the alveoli of the lungs into red blood cells. This is because the concentration of oxygen in the alveoli is high, and the concentration of oxygen in the red blood cells is low. Red blood cells have very thin cell walls, which allow oxygen to diffuse easily in and out of them.

Diffusion in plants

Plants use carbon dioxide from the air for photosynthesis. Carbon dioxide enters the leaves through small holes called stomata on the underside of the leaf. Spongy cells called mesophyll cells allow gases to diffuse easily in and out of the leaf. The stomata can open and close so the plant doesn't lose too much water.

More diffusion demonstrations

Making a cup of tea is another great diffusion demonstration. This diffusion activity using different shaped tea bags is great fun.

Spray perfume in a room. The smell will slowly spread through the available space.

Another example of the movement of substances important for living things is osmosis.

The post Diffusion Demonstration appeared first on Science Experiments for Kids.

We made these virus models to show how different viruses have very different structures. They are also different sizes ( our models are not to scale ) and infect different types of hosts.

At a very basic level each virus consists of genetic information in the form of either DNA or RNA surrounded by a protein coat called a capsid.

What you'll need

Play dough or plasticine

Toothpicks, pipe cleaners, cotton buds - optional

Model each virus using the play dough or plasticine, thinking about the shape and structure of the virus. Our viruses are not to scale. In reality Ebola is much bigger than the others.

Playdough Virus Models

Ebola

Ebola is a highly contagious, zoonotic ( can be transmitted to humans from animals ) virus with a high death rate in humans.

Ebola is linear, with an RNA genome.

Two species of fruit bats are thought to be the hosts of Ebola virus. It is then transmitted to animals when they eat food that has been in contact with bat faeces or saliva.

Ebola is spread through humans by contact with infected bodily fluids.

The first known outbreak of Ebola was in Africa in 1976. The biggest outbreak so far was in 2014 where the virus was seen in Sierra Leone, Guinea and Liberia. Around 11,000 people are thought to have died from the virus over the two year outbreak.

Symptoms of Ebola

Incubation period - 2-21 days

Fever, headache, weakness, nausae and blood clots which then cause bleeding into the surrounding tissue.

Ebola attacks every organ and tissue in the body.

Death within 8-17 days for between 5 and 9 out of 10 people infected.

Extension Task - Find out about Marburg Virus.

Suggested reading - The Hot Zone

Zika Virus

Zika virus is spread by mosquitoes, it's named after the Zika Forest in Uganda where it was discovered.

Zika virus can cause Zika fever, which is usually a mild infection in healthy people. However if a pregnant women contracts Zika it can lead to birth defects.

Outbreaks of Zika have occured in South and Central America, the Caribbean, Africa and parts of southeast Asia.

Symptons of Zika virus

Rash

Itching

High temperature

Headache

Joint and muscle pain.

Coronavirus

A new type of coronavirus started to spread around the world at the end of 2019. COVID-19 leads to flu-like symptoms and is spread via infected particles that get into the air when an infected person coughs, sneezes or even just talks. Virus particles can also survive for a period of time on surfaces, so if you were to touch a surface where the virus is and then your nose, mouth or eyes, you could becomes infected.

Not everyone who comes into contact with COVID-19 shows symptoms, some are asymptomatic.

The full impact of the COVID-19 pandemic that started in 2019 is yet to be seen.

Symptoms of COVID-19

Cold symptoms - sore throat, runny nose, general congestion

Muscle pain

High temperature

Nausea

Fatigue

Loss of smell or taste

Headache

Adenovirus

Adenoviruses are viruses that affect membranes of the respiratory tract, eyes, intestines, urinary tract and nervous system. They causes illnesses such as croup, colds, pneumonia and bronchitis. Adenoviruses are usually highly contagious and can survive on surfaces as well as droplets in the air.

Infections are usually mild and symptoms depend on which part of the body is affected.

Adenovirus infection of the stomach and intestines causes stomach pain, vomiting and diarrhoea.

Good hygiene is the best way to avoid adenovirus infections.

The post Easy Virus Models appeared first on Science Experiments for Kids.

A virus is a very tiny organism that can only live and reproduce inside another living cell. The cell the virus invades is called the host cell. The virus basically turns the cell into a factory to make more viruses which then invade more cells.

Viruses consist of a stand of genetic information ( DNA or RNA ) inside a protein shell called a capsid. Some viruses also have a membrane layer around them.

Viruses use cellular components of the host cell to reproduce. New viruses are then released from the host cell which then search for a new cell for themselves.

There are many different types of viruses which infect different hosts and have different structures. These play dough virus models are a great way to learn about viruses and their structures.

Examples of viral infections include

Influenza virus

Common cold virus

Measles

Chicken Pox

Norovirus

HIV - Human Immunodeficiency Virus

Ebola

Rabies

What happens when you are infected with a virus

Some viruses release poisons which make you feel poorly.

The majority of the time the human body can fight the virus and any medical treatment is to relieve the symptoms of the virus rather than destroy it, but for more severe infections such as HIV and Hepatitis medicines called antivirals can be used.

Some viruses stay in your body for a very long time. Herpes Simplex Virus lies dormant until a person is run down when it activates itself leading to a cold sore. This is why people often get cold sores after another illness.

Chicken Pox - caused by varicella Zoster Virus can reoccur as shingles in adulthood.

How do viruses spread?

Viruses are very small and light and are passed between people by touch, through water or in the air.

How do humans fight viruses?

It's all quite complicated but very simply, white blood cells in our blood engulf and destroy microbes that can cause us harm including viruses.

White blood cells produce antibodies to fight microbes. These often remain in the blood stream ready to fight the same infection again.

White blood cells neutralise poisons made by microbes.

Vaccines are available for some viruses which help us to become immune to the virus being vaccinated against.

Virus Facts

Viruses are the smallest microbe ( 1/1000000 mm). Most viruses cannot be seen with an optical microscope.

Viruses cannot reproduce on their own they need a host cell.

The study of viruses is called virology and scientists that study viruses are called virologists.

Viruses are not classed as living things. They can't reproduce or metabolise on their own.

The first human virus to be discovered was yellow fever virus in 1901 by US army physician Walter Reed.

Viruses don't just infect humans, they infect plants, fungi and even bacteria!

A virus that infects bacteria is called a bacteriophage!

Viruses have no nucleus.

The post What is a Virus? appeared first on Science Experiments for Kids.

The digestive system is made up of several organs working together to make an organ system ( digestive system ). This activity shows how to make an easy digestion system model using food and tights!

This activity can also be found in my book Gross Science!

What is Digestion?

Digestion is the process by which large, insoluble molecules of food are broken down into smaller, soluble molecules that the body can use.

Digestion starts in the mouth, where food is broken into smaller pieces as people chew. Food is mixed with saliva, which contains an enzyme called amylase. Amylase starts to break down carbohydrates in the food.

Food then passes down the oesophagus and into the stomach. The stomach contains stomach acid and more enzymes which break up the food further. Stomach acid is actually hydrochloric acid which kills most harmful bacteria and provides the optimum pH for enzymes to get to work.

As food is slowly released from the stomach into the small intestine, the liver adds alkaline bile to the mixture. This neutralises the stomach acid so as not to harm the small intestine and helps to break up fats.

The pancreas makes three digestive enzymes which are also added to the food mixture. These are:

Protease for digesting proteins.

Carbohydrase for digesting carbohydrates

Lipase for digesting lipids.

The small intestine produces even more enzymes to continue digesting proteins, carbohydrates and fats. Nutrients are absorbed through the walls of the small intestine and transported to cells in the body by the blood.

In the large intestine, water is absorbed from food, and undigested food is passed to the rectum as faeces.

The final part of the journey is when the faeces pass out of the anus, hopefully into a toilet!

The small intestine absorbs nutrients from food, and then the large intestine absorbs water and any nutrients not absorbed by the small intestine.

Undigested food becomes faeces or poo, which are excreted from the body via the rectum and anus!

Easy digestive system model using tights

You can make a very simple digestion model using one leg of a pair of tights as the small intestine.

What you need to make a digestive system model

Potato masher - or something else to crush the food with.

Bowl

Funnel

One small banana or piece of bread

One plain biscuit

Yoghurt- optional

Jar or bowl

30ml water

30ml orange juice

Green and red food colouring - optional

Medium-size sealable bag - stomach

Scissors

I leg from a pair of tights  - small intestine

Tray or plate

Digestion Model Instructions

Place the biscuit and banana into a bowl and gently crush with a potato masher. This represents the food being chewed. Pour the crushed food into an empty plastic bag and add the water. The water represents saliva.

Pour the orange juice into the bag ( this represents stomach acid). Seal the bag to prevent air from entering.

Squeeze the bag for about a minute, crushing the biscuits and banana further. This represents the food breaking down further inside the stomach.

Once the stomach contents feel like a thick liquid, cut a small hole in one corner and carefully squeeze into the open leg of the tights ( small intestine ).

At this point, you can add a little red and green food colouring, but this is not necessary. The red food colouring represents dead red blood cells that are being disposed of, and the green represents bile, which is released by the liver.

Hold the tights over the tray or a bowl and gently squeeze the liquid out. The liquid on the tray represents the nutrients the body absorbs and uses.

Keep squeezing until no more liquid comes out. If you used food colouring, wearing gloves for this part might be a good idea.

The food left behind in the tights represents waste products that cannot be absorbed.

Cut a hole in the bottom of the tights and squeeze the contents into the jar. This is the poo!

Digestive System Model Challenge

Change the food you “digest” and investigate to see if you can make a different colour poo!

Did you know the stomach walls are made of muscle, which mixes the food, helping to break it down?

The small intestine contains lots of thin structures called villi. These give a very large surface area to absorb food molecules.

Digestion in a Nutshell

Food is initially broken down in the mouth as you chew, helped by amylase ( an enzyme found in saliva )

It then passes down the oesophagus into the stomach, where it mixes with stomach acid and enzymes.

The liver makes bile to help break up fats and neutralise the acidic mixture heading to the small intestine from the stomach.

The pancreas adds more enzymes to the mix.

Food is broken down further in the small intestine, where small usable molecules are absorbed through the small intestine walls into the blood.

Water is absorbed by the large intestine.

Waste products are expelled via the anus!

If you enjoyed this activity, I have lots more human body investigations suitable for kids of all ages you might like.

The post Easy Human Digestive System Model appeared first on Science Experiments for Kids.

I've lost count of the number of water science experiments we've done over the years. Water is pretty amazing. Did you know it is the only natural substance to exist in three physical states at temperatures naturally occurring on Earth?

Facts about Water

• Water covers about 70% of the surface of the Earth.
• Water expands when it freezes.
• We need water to survive.
• Water expands when it freezes.
• Water can move upwards!!

Water has lots of properties that make it just brilliant for simple science investigations!

Water Science Experiments and Investigations

Freezing and Melting Investigations

Freezing and melting investigations are always fun. For younger children, let them play with ice cubes while they melt. You can freeze small toys inside to make this a bit more exciting.

We had great fun with our LEGO ice excavations recently, but you can also freeze superheroes, bugs or anything else that might spark an extra interest.

Just getting the child to recognise that the ice is cold and how that feels on their fingers is a great sensory experience. Remember to let the ice melt a little first, as ice can be sticky when first removed from a freezer.

Water Cycle Experiments

Make a mini water cycle or a water cycle in a bag. These are great science activities for older children and help explain a tricky concept.

Water and Density

Density is a tough concept to grasp, but hopefully, this density science trick is interesting and simple enough to help it all make sense. Salt increases the density of water, so the coloured salty water doesn't mix with the less dense water on top!

Density jars are also great fun. Children can try and find different small objects to float on the layers. These can be very simple and just contain water and oil, or children can experiment with layers of washing up liquid (dish soap ), treacle, honey and other non-toxic liquids.

Transport of Water in Plants

Learn about transpiration and make some pretty coloured flowers. I love this activity. If it works well, you can see the path the water takes to reach the edge of the petals.

Sinking and Floating Experiments

How about some simple sinking and floating experiments? This is great for young children, who love to watch objects sink and float. Older children can make a plasticine boat and discover whether an item that previously sank can float in the boat. Or, try and predict which objects will sink and which will float.

Did you know you can use a bit of clever density science to make an egg float?

Children can also make a lemon sink if they understand why it floats in the first place!

Oil and Water Experiments

Find out why oil and water don't mix. We've also demonstrated this using coloured water and pipettes, which was brilliant fun.

Osmosis Experiments

Learn about osmosis ( water passing through a semi-permeable membrane ) using eggs. The term osmosis might sound complicated, but this egg demonstration makes it more understandable, and don't worry if your children don't understand straight away or are too young. It's still fun to watch the eggs expand and then shrink.

Absorbing Water

How about exploring absorption using sugar cubes? The fact that you can watch the water rise up the cube is brilliant and appeals to children of all ages.

A walking water investigation is another excellent way to learn about how water is absorbed by different materials.

Water Powered Rocket

Learn about air pressure with this very cool water-powered bottle rocket.

Filtering Water

Discover how to clean water with this easy filtering activity using paper towels or using sand and stones.

Another idea is to investigate how to clean up water after an oil spill.

Is it waterproof

Investigate which materials are waterproof by using them as a roof for a LEGO house and investigating whether they keep the floor dry.

Dissolving in Water

Predict and test which substances will dissolve in water.

Do you have any more water science experiment ideas for us?

More Science for Kids

Try my fun science tricks or easy Fairy Tale STEM challenges!

If you enjoyed these experiments, don't forget to check out the rest of my 100s of other science experiments for kids, too!

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Today I have lots of ideas for preschool science experiments to share. Science isn't just complex experiments for older children. Science is all around us and can be enjoyed and explored by children of all ages. Even just simply encouraging children to touch objects with different textures or observe the world around them is introducing simple scientific concepts that will hopefully inspire a love of science as they grow.

I've compiled a collection of our favourite preschool science experiments, including STEM and STEAM experiments. You'll have the BEST time exploring with your child if you give them a go.

Let us know what you think or if you have any other fun preschool science ideas for us to try.

Easy Preschool Science Experiments

Magic Opening Flowers

These magic opening paper flowers are easy to set up and work brilliantly! All you need is paper, scissors and a tray of water.

Filter Paper Butterflies

Filter paper butterflies are a lovely creative science activity. Learn a little about chromatography when making the butterfly's wings, and maybe read a book about butterflies and caterpillars once the butterflies are finished. These also make a lovely classroom decoration.

How many feet tall are you?

Work with children to discover how many feet tall they are. If they measure several people, there might be a pattern to spot too!

Numeracy at Home/School Box

Explore numbers with a Numeracy at Home box. This simple idea is great when children have spare time or finish a task early!

Jumping Frogs - Static Electricity Activity

Learn about static electricity with our jumping frogs

Another fun way to learn about static electricity is to rub a balloon on your hair to make it stand up on end or have a competition to see how many balloons you can stick to the wall at once!

Waterproof Investigations for Preschoolers

Investigate how and why some materials are more waterproof than others with this fun activity using soft toys.

Magnet Maze

We love magnet mazes! These can be made for any theme, and you can also add numbers and letters.

Gruffalo Shadow Puppets

Make a Gruffalo shadow puppet after reading the book. We made a mouse puppet, but anything from the book or more than one puppet would be amazing too.

Make a Filter

Ask children to design and make their own filter. We find LEGO or DUPLO makes the perfect mixture to filter.

Colour Mixing

There are many fun ways to learn about primary and secondary colours and how they mix. We loved our colour mixing squishy bags and colour mixing with food colouring and water. You could even make a colour mixing water wall.

Sort Materials

Set up a Little Mermaid themed sorting tray to sort items by colour, size or material.

Fairy Tale Science Experiments for Preschoolers

Make a raft for the Billy Goats, a house for the Three Little Pigs, witchy potions and lots more great fairy tale preschool science experiments.

Messy Preschool Science Experiments

Our messy science station will surely be a big hit with kids of all ages. Experiment with oil, water, food colouring and baking soda for wonderfully messy science play!

You might also like my collection of superhero science activities!

Can you think of any more science experiments for preschoolers we would like to try? Do let us know if we've missed anything you love.

Follow our Preschool Science Experiments Pinterest board for even more preschool science ideas.

Don't forget we have lots more fun science experiments for kids, so do let us know if you try any and what you like.

The post 10 Fun Preschool Science Experiments and Activities appeared first on Science Experiments for Kids.

I can't really take the credit for these awesome animal cell models as it was my son's science homework earlier in the year, but he did such a good job I wanted to share on here.

His first thought was to make a spherical cake model, which I thought sounded a bit tricky, so we decided jelly might an easier way to go. It took several attempts to get a good model as some of the sweets he tried melted into the jelly, anything with a coloured coating didn't look good for very long.

Jelly Animal Cell Model

Did you know all living things are made up of very small building blocks called cells?

What are the differences between animal and plant cells?

Animal and plant cells have three differences.

Only plants cells have the following features:

Cell Wall - this is a rigid coating of cellulose which gives support to the cells.

Vacuole - this is a large space filled with a solution of sugar and salts ( cell sap )

Chloroplasts - these contain chlorophyll which is used for photosynthesis.

Plant cells are much bigger than animal cells ( 40 x as big )

Both animal and plant cells have:

A Nucleus - this controls what the cell does

Cytoplasm - this is where all the chemical reactions occur in the cell.

A Cell Membrane - this is a think skin around the cells which holds the cell together and controls which substances pass in and out of the cell.

Golgi Body - sorts and processes proteins

Mitochondria – this is like the battery of the cell and provides energy using a process called respiration.

Lysosomes – these get rid of waste and also destroy a cell when it dies.

What is a tissue?

A tissue is a group of similar cells working together.

What is an organ

An organ is a group of different tissues working together.

A group of organs work together to form an organ system. The human body has 11 organ systems including respiratory, circulatory, nervous and excretory.

We made two types of animal cell models one using jelly and one using modroc ( plaster bandage ).

We didn't label the cell membrane as that is the edge of the jelly and the cytoplasm is the inside of the jelly.

This is the jelly animal jell model.

Plaster bandage animal cell model

More cell biology for kids

If you enjoyed this activity why not try our fun candy DNA model?

We also have an easy jelly plant cell model you could try!

These printable animal and plant cell revision cards might be handy too. Click the image to download.

Contains affiliate links

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This blubber experiment is a simple, easy way to demonstrate how animals ( not just polar bears ) stay warm in cold temperatures. There are some fun polar bear facts at the bottom of the page, too. How many do you already know?

The same experiment works for talking about how penguins stay warm in winter as well!

How do Polar Bears stay warm in winter?

First, we talked about how some animals live in a very cold environment, and I asked the children how they thought those animals stayed warm. The first answer was that animals have fur to keep them warm, and then we talked about how humans stay warm in cold weather. We put on extra clothes, we warm up our environment by heating it, and we stay indoors longer. Animals don't have those options, but one way they can stay warm is by growing a thick layer of fat, which acts as an insulator to keep them warm.

Polar Bears are extremely well insulated and have a layer of blubber that can be up to 10cm thick, covered with another 15cm of fur. They also have black skin under their fur, which helps trap heat.

We set up this simple activity to demonstrate how blubber helps keep animals warm.

Blubber Experiment Materials

Lard or shortening

Latex gloves

Ice or snow

Water

Washing up bowl

Stopwatch

Blubber Experiment Instructions

Place ice and water in a washing up bowl.

Carefully place your hands in the ice water and time how long you can keep them in the water before it gets uncomfortable - be careful not to leave them in longer than that.

Put the glove on and cover it with lard.

Put the gloved hand in the ice water and record how long it takes to feel uncomfortable this time.

You should find that the lard acts as an insulator and protects your hand from the cold of the icy water.

What is an insulator?

An insulator is something that doesn't easily allow heat to escape. In this investigation, the lard is insulating your hand from the icy cold water.

Blubber Investigation Extension Ideas

If you have a thermometer, can you record the water temperature?

How do polar bears stay warm in winter?

Some animals hibernate. They build a den or burrow and sleep for the colder months. Their body temperature drops and their heart rate slows down to conserve energy.

Other animals migrate for Winter, which means they move to a warmer climate where food is available.

Some animals adapt to the change in climate. They grow warmer fur or feathers or grow a layer of insulating fat. Fat also acts as a food store when food is scarce.

Polar Bear Facts

Did you know that polar bears only live at the North Pole ( Arctic ) and penguins at the South Pole ( Antarctic )?

Polar bears mostly eat seals.

Female polar bears usually weigh about half as much as male polar bears.

Polar bears can run at speeds of 25mph on land.

Did you know polar bears can live to around 30 years old?

Polar bears have hollow, colourless fur, which traps the sun's heat to keep them warm.

Polar bears can overheat in summer when temperatures are the highest. They often roll in the snow to cool down.

Polar bears have an amazing sense of smell and can smell seals 1km away!!

This post is also part of my Around the World in 50 Experiments series!

The post How do Polar Bears stay warm in winter? appeared first on Science Experiments for Kids.

I still remember learning about osmosis at school many years ago. I don't know why that particular memory has stayed with me so strongly, maybe because it was hard to understand. Whatever the reason, osmosis is a term I've never forgotten the meaning of.

Definition of Osmosis

Osmosis is the net movement of water molecules across a partially permeable membrane from a region of higher water concentration to a region of lower water concentration.

or

Osmosis is the net movement of water molecules across a partially permeable membrane from an area of lower solute concentration to an area of higher solute concentration.

The important thing to remember is that osmosis is the movement of WATER MOLECULES( or other solvent ), not the particles dissolved in the water. For example if you split a beaker of water into two halves with a semi permeable membrane and added salt to one side, water would move from the side of the beaker with no salt into the salty side.

What is a partially permeable membrane?

A partially permeable membrane has very small holes in it. Tiny water molecules can fit through, but not bigger molecules like sugars.

Osmosis Example

Try soaking a raisin in water. What happens? It should swell up a little. This is because the water moves from where it is in high concentration ( the water ) into the raisins which have a low water concentration. Water keeps moving by osmosis until equilibrium is reached, this is when the concentration of both solutions is the same.

Another fun way to illustrate osmosis is with eggs as they have a handy semi-permeable membrane.

Easy Osmosis Experiment

You'll need

Two eggs

Water

Two glasses or jars

Vinegar

Sugar

A pin

Remove the shell from two eggs

Place two eggs in a container of vinegar for about 24 hours. The eggs should be completely submerged.

After about 24 hours, remove the eggs and gently rub the shell under cold running water. You should be able to remove most of the shell.

If it won't all rub off, put the eggs in fresh vinegar for another few hours.

Shrink an egg

To shrink the egg you need to put in in a concentrated solution so water molecules will move from the egg into the solution..

Stir about three tablespoons of sugar into a glass of water and stir until all the sugar has dissolved.

Place one egg in this solution.

Grow an egg

Place the second egg in a glass of plain water.

Leave the eggs for about 24 hours. Can you predict what will happen?

Note how the egg in the water sinks to the bottom of the glass while the one in the sugar solution floats. This is because the sugar solution is more dense than the water.

Our egg in the water expanded while the egg in the sugar solution shrank. I used dark sugar, which is why the solution looks brown/red, but any sugar will work.

Prick the egg from the water with a fine needle and watch a jet of water shoot out!

How do you think you could rehydrate your shrunken egg?

Why does the egg grow and shrink?

Our concentrated solution was the sugar solution. The dissolved sugar molecules cannot pass through the semi-permeable membrane of the egg, but the smaller water molecules can. Water molecules move from where they are in higher concentration ( inside the egg ) to where they are in lower concentration ( the sugar solution ) until equilibrium is reached. Therefore water molecules move from inside the egg to the sugar solution. This makes the egg shrink as the net movement of water is out of the egg.

To rehydrate the egg, place it in plain water. In this instance the concentration of water molecules is higher in the water than inside the egg so the net movement of water molecules is from the water into the egg!

When we pricked the egg soaked in water, water shot out. This is because the egg had absorbed so much extra water that the pressure inside increased.

Why does egg shell dissolve in vinegar?

The egg shell dissolves in the vinegar as the acetic acid reacts with the calcium carbonate of the shell. Carbon dioxide is given off during this reaction, which is the bubbles of gas you see.

More osmosis experiments

Weigh the eggs at each stage to monitor the loss and gain of water.

Add food colouring to the water and watch the eggs absorb the coloured liquid.

What do you think would happen if you left an egg in a glass of golden syrup?

Try measuring the egg at each stage of the investigation.

We used thread to measure the diameter of the egg at its widest point after the shell was first removed, after soaking in vinegar and after soaking in golden syrup.

The longest thread is from when the egg was soaked in water. This is because the concentration of water inside the egg was lower than outside the egg, so water moved into the egg.

The shortest thread is from the egg soaked in golden syrup. Water moved by osmosis out of the egg into the golden syrup because the concentration of water inside the egg was higher than outside.

Don't forget to wash your hands after handling raw eggs

More egg experiments for kids

Learn about tooth decay with eggs. Did you know an egg shell is similar to the outer coating on our teeth?

Find out how to transform egg white into meringue and make a tasty dessert at the same time.

Finally, did you know you can make an egg bounce?

The post What is Osmosis? appeared first on Science Experiments for Kids.

The lungs are an essential organ for all mammals. Lungs have several features which make them perfect for exchanging gases.

• a very large surface area, thanks to a network of small tubes and tiny air sacs called alveoli.
• they are moist
• and have a good blood supply

Today, we're going to find out how lungs work by making a lung model.

The lungs are part of our breathing system, which has two functions:

• ventilation – the movement of air into and out of the lungs
• gas exchange – gases are exchanged between tiny sacs called alveoli and the blood.

Under the lungs is the diaphragm, a muscular sheet separating the lungs from the abdomen. The diaphragm moves up and down to increase the space in the chest, like the balloon at the bottom of the model.

To make a model lung you'll need

• A plastic bottle
• A straw
• An elastic band
• Scissors
• Two balloons
• Play dough

The bottle acts like the chest cavity, the balloon at the bottom is like the diaphragm and the balloon in the centre is like a lung.

Instructions for making a model lung

1. Carefully cut the bottle roughly in half. Ask an adult to help. Discard the bottom half.

2. Tie a knot in one end of one balloon and cut off the opposite end.

3. Stretch the balloon around the bottom of your plastic bottle.

4. Place a straw in the neck of the other balloon and secure it tightly with the elastic band but not so much that you crush the straw. The air must flow through, so test it with a little blow through the straw to see if the balloon inflates.

5. Put the straw and the balloon into the neck of the bottle and secure them with the play dough to make a seal around the bottle - make sure that again, you don't crush the straw, but air can flow through.

Hold the bottle and pull the knot of the balloon at the bottom. What happens?

You should find that the balloon inside the bottle inflates, and as you let go the balloon deflates.

Why does this happen?

As the knotted balloon is pulled it creates more space inside the bottle. Air then comes down the straw and fills the balloon with air to fill the space! This is like breathing in.

When you let go of the knot the space no longer exists, so the air from the balloon is expelled making it deflate.

Inside the lungs is a network of tubes which allow air to pass through. Air is warmed, moistened and filtered as it travels through the mouth and nasal passages. It then passes through a network of tubes, eventually reaching tiny sacs called alveoli which is where gas exchange occurs.

How do lungs work?

This lung model demonstrates how the lungs work. Air is taken in through the mouth and nose, passes down the windpipe and into the lungs. The diaphragm at the bottom of our chest moves down to create more space. As we breathe out the diaphragm raises again. The knotted balloon represents the diaphragm and the balloon inside the container represents a lung. That's how lungs work!!

More ideas for learning about the lungs

Create a labelled diagram of the gas exchange system.

Use balloons to make a very simple model of the lungs.

More human body science ideas

Create and build a DNA model from candy

Try this super simple heart rate investigation.

Make your own stethoscope with a cardboard tube, tape and a funnel.

If you liked this post, we'd love you to follow us on Facebook, where we post fun science ideas daily!

If you enjoyed this activity, do check out my other easy science investigations for kids of all ages.

The post How Do Lungs Work? Make A Model Lung appeared first on Science Experiments for Kids.

This Candy DNA model is a great way learn about the structure of DNA.

Did you know that 99.9% of the DNA of each person is the same? It's just that tiny 0.1% that makes us all different! Isn't that amazing? Humans also share 60% of their DNA with fruit flies which is even more incredible!

Image taken from Snackable Science

Who discovered the structure of DNA?

James Watson and Francis Crick along with Maurice Wilkins and Rosalind Franklin discovered the structure of DNA in 1953. Before this groundbreaking discovery scientists knew that DNA carried genes which parents passed onto their offspring but didn't know how it worked or what DNA looked like.

Rosalind Franklin produced x-rays which were central to this amazing discovery, although her contribution wasn't acknowledged until after Crick, Watson and Wilkins received their Nobel Prize.

What does DNA stand for?

DNA stands for deoxyribonucleic acid, it's a long thin molecule a bit like a recipe containing instructions or code which tells cells how to behave and grow.

What is DNA made from?

DNA is made from nucleotides. There are four different nucleotides: adenine, thymine, cytosine and guanine. We call these bases and usually refer to them by the first letter of their name.

A pairs with T and G with C.

Why is DNA shaped like a double helix?

DNA consists of a 2 backbones holding together the nucleotides. The two backbones twist together giving a double helix shape with the two strands  held together by hydrogen bonds between the base pairs.

How does DNA replication work?

DNA can copy itself by separating a bit like a zip. The newly unpaired nucelotides attract new partners building two new identical helices.

What is a gene?

A gene is a set of instructions held on a string of DNA telling a cell how to make a specific protein or enzyme molecule. The set of instructions ( or code ) is made up of codons. A codon is set of 3 nucleotides. For example a string of codons could look like this:

GAC ATC GGA AAT

Genes carry information that determines your traits ( features or characteristics that are passed on to you by your parents ).

The DNA in a gene provides instructions for making proteins which are the building blocks of everything in your body. Proteins help bodies to grow, develop and stay healthy.

What is an enzyme?

Enzymes speed up chemical reactions.

What is a chromosome?

Chromosomes are found in the nucleus of cells and are made from very long DNA molecules.

Human body cells have 23 pairs of chromosomes.

What is a genome?

All the genetic information in an organism is called its genome. You might have heard of the Human Genome Project which aimed to sequence the entire human genome using DNA from several people to find an average sequence. The project was finished in 2001, but scientists are still working to identify single genes.

How to make a DNA model

We've been busy creating very simple DNA models using sweets.

What you need to make a candy DNA model

Liquorice sticks or other long thin candy

Something soft for the bases - we used jelly tots and  jelly babies chopped in half. I tried with midget gems first but they were too hard to push the cocktail sticks through. Small marshmallows would be a good alternative too.

Cocktail sticks

Instructions for making a candy DNA model

Remember C and G and T and A always pair up, so assign a colour to each nucleotide and add pairs of sweets to your cocktail sticks.

Attach each end of the cocktail sticks to your liquorice, spacing them evenly apart.

Once you have a long enough string, twist it to give the spiral shape of a double helix. This one is a little on the short side, so our next challenge is to make a bigger version.

What do you think of our Candy DNA model?

Fancy learning more about the discoveries of famous scientists? We've got some great famous scientists experiment ideas too.

More DNA Models

This origami DNA Model looks amazing!

These DNA models made with straws and tape look fantastic too!

If cell biology is your thing, we also have a cool jello plant cell model.

The post Candy DNA Model - Edible Science Experiment appeared first on Science Experiments for Kids.

This hands-on chicken life cycle sensory bin is brilliant for working on fine motor skills, whilst introducing the concept of a life cycle. We used a chicken as the example as most children are familiar with eggs and chickens making it a little easier to understand.

What you’ll need:

• Plastic eggs – the hen lays an egg, which can only become a chick if fertilized by a cockerel.
• Chicks – the chick hatches from an egg by pecking a hole in the shell.
• Feathers – chicks are covered with fluffy feathers to keep them warm
• Hen and cockerel models - chicks grow into chickens!
• Rice or pasta – these can be left plain or dyed yellow using food colouring.
• Tweezers
• Paper Plate
• Pens

How to make a chicken life cycle sensory bin

Pour the rice or pasta into a tray. If you want to use coloured rice, simply pour some rice into a sealable bag, add some food colouring, and give it a good shake, so all the rice is covered and leave to dry.

Spread the eggs, chicks, feathers and hen around the tray.

Ask the children to use tweezers to pick out each part of the chicken life cycle in order and place them on a paper plate.

Children can then draw arrows between items to show the order of the life cycle.

More Life Cycle Activity Ideas

Can you make a sensory bin for a frog's life cycle? How would it be different?

Can you create a food chain featuring a chicken?

Did you know chickens are the most common bird on earth and hens can lay around 300 eggs every year!

More life cycle activity ideas

Try our easy edible butterfly life cycle

Or how about these minibeast life cycle activity ideas?

We love this frog craft life cycle from Still Playing School.

This butterfly life cycle necklace is lovely from Fun-a-Day.

Playdough to Plato has some super cute life cycle hats

We've also got some more minibeast life cycle activities here.

The post Chicken Life Cycle Sensory Bin appeared first on Science Experiments for Kids.

Have you ever wondered how water is transported up the stem of a plant against gravity? This transportation process is called transpiration. You can demonstrate transpiration easily with simple transpiration experiments.

You might also like our plant respiration and photosynthesis investigations.

Transport in Plants - Transpiration

Transpiration occurs when water on the surface of leaf cells evaporates and then diffuses out of the leaf. This draws water out of the xylem cells inside the leaf to replace the evaporated water. Xylem cells form a continuous tube from the leaf to the roots, which acts like a drinking straw, giving a flow of water from root to leaf.

Transport in Plants - Capillary Action

Transpiration helps another process called capillary action to take place, which is how water moves through a plant.

Water molecules are attracted to the molecules of the inside of the stem. It is this attraction which helps force the water up from the ground and around the plant.

Transpiration Experiment

You can demonstrate capillary action and transpiration by placing a flower in a glass of coloured water. After a few hours, the petals will turn the same colour as the water. This is because the coloured water is transported up the stem and into the petals.

Transpiration Definition

Transpiration is the movement of water through a plant and evaporation from leaves, stems and flowers.

Water moves through the xylem vessels of a plant in a continuous transpiration stream.

root - stem - leaf

Functions of Transpiration - transport in plants

Transport of mineral ions

Transport of water to all parts of the plant, including leaf cells where it is needed for photosynthesis.

Keeping leaves cool as water evaporates from the surface.

What factors affect transpiration?

There are three forces involved in this process of transporting water in plants.

Adhesion allows water to stick to the organic tissues of a plant.

Cohesion keeps the water molecules together.

Surface tension holds the water molecules together as they are transported through the plant.

Capillary Action Definition

Capillary action is the movement of a liquid through a narrow space caused by cohesion, surface tension, and adhesion.

For capillary action to work, the adhesion force between the water and plant tissues must be stronger than the cohesion between water molecules.

When a water molecule is more attracted to the plant, it is pulled towards the plant tissue, but as water molecules are highly attracted to each other, the first molecule brings further water molecules with it.

Plants use two different transport systems, both of which are rows of cells that form tubes around the plant. The xylem transports water and minerals from the roots to the leaves, while the phloem moves food substances from the leaves to the rest of the plant.

Plant Stem Model

We used straws to make a very simplified model of a plant stem. The xylem is the centre yellow part, and the phloem is the blue straws.

Easy capillary action experiment

This simple experiment is a super easy and fun demonstration of capillary action and water transport in plants.

Materials

Tray

Water

Paper - sugar paper works best

Scissors

Method

Cut out several flower shapes from the sugar paper.

Curl up the edges and place on the surface of the water.

Watch as the flower opens up.

How does capillary action work?

Paper is made of many fibres. As they absorb water, they swell, and the paper expands, allowing the flower shape to open up.

This process is called 'capillary action'. Water uses this process to move along the tiny gaps in the fibres of the paper. This occurs because the adhesive force between the water and the paper is stronger than the cohesive forces inside the water itself. This is the same process by which water travels from the root up the stem to the petals of a plant.

More transpiration experiment ideas

The DK Website has some great plant facts for kids.

We also used two syringes to show water travelling up the stem of a LEGO plant, which is quite a nice model for younger children.

Suitable for Key Stage 2 Science

Plant Science

Investigate the way in which water is transported within plants

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Do you know why we have bones? We have some fun activity ideas to share today to help you find out!

Fun facts about bones

A human has 206 bones!

There are 26 bones in the human foot.

The femur is the longest bone in the human skeleton.

When babies are born, they have about 300 bones, but some fuse together to form the final 206 adult bones.

What is a skeleton

The human skeleton is made up of all our bones and grows as we grow.

Did you know your skeleton has three main jobs?

Why do we have bones? Functions of the human skeleton

Skeleton Function 1 - Support

Your skeleton stops you from being all floppy, acting like a scaffold to hold up the soft tissues of your body. The spine is a good example of a part of the skeleton with a supportive role. Place your hands on the centre of your back. Can you feel your spine? It runs from your head to your pelvis and consists of 33 small ring like bones called vertebrae.  It holds up your head and allows your body to bend. The spine also protects the spinal cord, which runs through the centre.

Can you thread some cotton reels onto a piece of string? This is a bit like your backbone. The cotton reels represent the vertebrae and the string the spinal cord. This would also work well using egg cartons cut up into segments.

Spine Models - Why do we have bones?

Spell Outloud made a great model of a spine using hair bands and pool noodle segments.

This candy model of a spine from Adventures in Mommydom is amazing, too!

Skeleton Function 2 - Protection

Your skeleton is hard and strong, providing the perfect protection for your soft internal organs. A good example of part of the skeleton with an important protective role is your skull, which helps keep your brain safe if you bang your head. Can you think which part of the skeleton protects your heart and lungs?

Skeleton Function 3 -Movement

Bones are rigid, but they have clever joints allowing us to move with a bit of help from muscles. If you wiggle your fingers can you see the bone joints?

If you bend your arm, can you see the bulging muscle above your elbow? This is your bicep.

Children can also draw around themselves and draw as many bones as possible.

So, that's why we have bones!

What is a joint?

A joint is where two or more bones meet. Some are fixed in place, some move a lot, and others move just a  little.

Hinge joints -  found in the elbow and knee allow people to bend and straighten arms and legs.

Ball and Socket joints which are found in the shoulders and hips allow movement in different directions. Did you know the longest bones in the body are found in the arms and legs? These bones are shaped like a tube and are very strong. A piece of paper on its own is not very strong at all, but if you roll it up and stand it on its end, it will stand up on its own and even support the weight of something on top. We discovered this when we learned about strong shapes.

Make a bendy bone

To make bendy bone, soak a chicken bone in vinegar for a few days, you should find that the bone becomes bendy. This is because the vinegar reacts with the calcium carbonate in the bones, breaking it down and making the bones softer.

How can you keep your bones healthy?

Find out how to keep bones healthy and practice fixing broken bones on a doll with Modroc.

Do you have any fun activities related to bones to share?

More activities for learning about bones

We love this life size skeleton from Fun at Home with Kids

The Imagination Tree has a fun math game all about bones.

I Can Teach My Child explains why we need muscles and bones using a pancake and a cookie.

Even more bone science ideas

Try some easy Halloween science with one of my fantastic Halloween Science Experiments

Or try one of our other fun ideas for learning about the human body.

Suitable for Key Stage 1 Science

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This post is all about adding a bit of science sparkle to role-play. The activities should hopefully add a stimulating and educational twist to an already fun game. My little boy is usually a bit reluctant to join in with role-play games, but if I add in a task or some props, he is much more enthusiastic.

Here are just a few of our favourite ideas.

Detective Role Play Ideas

Make a disguise/camouflage

Encourage children to create a camouflage outfit. This could be something as simple as green and brown clothing for playing in a garden or something more adventurous.

Give Directions

Ask children to draw a map of the house or garden so another spy can find them. Older children can write instructions to sit alongside the map.

We tried this by counting the number of steps and giving instructions left, right, forward, and backwards.

Make a Magnifying Glass

Make a magnifying glass to help with finding clues. We made one from an empty water bottle.

Take some fingerprints

Children will love taking fingerprints of a suspect. This is also a great way to learn about fingerprints being unique!

Send a secret message.

Make a secret spy code like Inspiration Laboratories or write a message with invisible ink?

We designed this code using symbols.

Track your friends

Playing a tracking game where one person is very quiet, and the others have to work out where they have gone.

Can you think of any more detective role-play ideas for us?

More role play science ideas

Learn about Flowers with flower shop role play.

Add some fun science to a Doctor role-play game.

The post Playing Detective - add some science to role play appeared first on Science Experiments for Kids.

Why do plants need water?

Plants need water to germinate.

We saw this with our bean in a jar. Water is needed to activate the process of germination, it also softens the seed making it easier for the plant to break through.

Photosynthesis

Photosynthesis is the process by which plants make energy to grow. Photosynthesis requires sunlight, water and carbon dioxide. We demonstrated what happens when a plant cannot photosynthesise when we made our cress caterpillar.

Nutrient transfer

Plants need water to absorb nutrients from the soil.

Transpiration

Transpiration is the process by which water moves up the stem of a plant from root to leaf when water is lost from the plant due to evaporation occurring at the leaves. This continual flow of water and nutrients keeps the plant's cells firm. If the cells become short of water, the plant starts to wilt.

We can demonstrate transpiration by placing white flowers in coloured water, the water travels up the stem to the petals which become coloured like the water.

Have you ever noticed your plants wilting? Did they revive after you watered them?

Suitable for Key Stage 1 - Living things and their habitats

Science concepts

Germination

Transpiration

Photosynthesis

The post Why do plants need water? appeared first on Science Experiments for Kids.

The idea is to observe what grows on potatoes over a period of time. We boiled the potatoes in water for 10 minutes first to destroy any microorganisms already present on the surface and then touched one of them with dirty hands, leaving the other untouched.

Our hypothesis was that micro-organisms from our hands would have been transferred to the potato when we touched it, and so that the potato that had been touched would grow more bacteria than the clean potato.

We also added a potato left in the air and one in vinegar to see what would happen.

Potato Investigation

You'll need

• Two small potatoes sliced in half
• Boiling water - ask an adult to help
• Vinegar
• Four containers with lids

Instructions

• Boil the potatoes for 10 minutes. This is to destroy any microorganisms already present on the skin.
• Carefully remove one potato with a spoon and place it into a jar, cover the jar and label it. This is the clean potato. Seal the jar.
• Remove another potato but don't cover this one. Leave this one exposed to the air.
• Remove a third potato and place it in a jar containing vinegar and seal the jar.
• Finally, remove the last potato, let it cool enough to hold and then roll it around your hands before placing it in a sealed jar.

Leave the jars on a window sill for a few days and observe any changes.

Once you've finished making observations dispose of the potatoes carefully. Ask an adult to help.

Results

Potato exposed to the air

The potato exposed to the air shrivelled up a little bit, and there was some evidence of micro-organism growth.

Clean potato

The clean potato ended up quite slimy, with some possible micro-organism growth.

Potato exposed to dirty hands

The dirty potato didn't seem to have more evidence of micro-organism growth than the clean potato.

Potato in vinegar

The potato kept in vinegar looked mostly unchanged.

What happened?

You can see that the vinegar has definitely preserved the potato. This is because vinegar is an acid, and microorganisms, find it hard to grow in such a hostile environment. That is why we pickle things to make them last longer.

I was hoping to see more growth on the dirty potato, but with science, things don't always work out as you expect. It could be that my jar wasn't airtight, or our hands were actually super clean!

More science ideas for learning about microorganisms

Find out how to stop apples from rotting by preventing the growth of bacteria and other microorganisms.

Learn about the wonders of snot by making a snot trap!

Find out how bacteria are different to viruses.

Finally, if you've got a spare potato have a go at making a potato battery!

The post Growing Microorganisms - Dirty Potatoes appeared first on Science Experiments for Kids.

Just before each beat, the heart fills with blood. It then contracts, which squeezes the blood along.

When you need more energy, such as when running, the heart beats faster to pump more oxygen around the body. When your heart beats, it sends a wave of pressure through all your veins. You can feel this pressure in some areas of the body (such as when a vein passes over a piece of bone). We call this your pulse. One place to feel your pulse is on your wrist in a straight line at the base of your thumb.

If you count your pulse for 1 minute, that gives you your pulse rate. You can do it for shorter periods, but you must remember to convert it to beats per minute. So, if you time it for 30 seconds, you would have to double your pulse count to get the number of beats per minute.

When the heart beats faster, the pulse rate is higher.

Heart Rate Investigation

How does exercise affect heart rate?

• A stopwatch
• Pen/Paper
• Space to move around

How to set up a heart rate investigation

• Record pulse rate at rest by counting pulse beats on the wrist for 1 minute.
• Run around outside or do star jumps for 1 minute.
• Immediately record pulse rate again
• Rest for 1 minute.
• Record pulse rate again.
• Find out how long it takes for the pulse rate to return to the resting level.

Results

Use my handy heart rate and exercise investigation results table to record your results or design your own!

This activity helps children understand

The heart pumps to circulate blood around the body.

The effect of exercise on pulse rate.

For younger children, draw around them on a big sheet of paper and mark where the heart is.

More human body science for kids

Did you know you can make a stethoscope with a cardboard tube and tape?

We love this DNA candy model!

Make a model of a heart or a model of a lung.

This digestion model for kids is also great fun!

Finally, how about a play dough model of the brain?

Science concepts

Heart rate

Pulse rate

Circulation

The post Easy Heart Rate Investigation for Kids appeared first on Science Experiments for Kids.

Where possible I always get my children to wash their hands before eating. The bigger two have made up a song to encourage little H to wash hers properly, it goes something like this:

Rub and scratch, rub and scratch

Or you'll get worms and germs

worms and germs.

la la la la

Lovely, don't you think?

We did a very simple activity today to show how dirt and germs can spread.

The glitter is meant to represent dirt and germs we can't see, and show how easily they pass from one person to another.

I was very careful to explain that not all germs are bad, and they shouldn't worry about holding hands, but should wash them before eating if they can.

The post Germs and worms appeared first on Science Experiments for Kids.

Did you know arm span ( also known as wingspan or reach ) is approximately equal to height?

How to calculate arm span

We tested this against a wall using chalk to mark our reach and then standing next to the wall to see if it matched our height. You should measure from fingertip to fingertip and not have a flat hand, as in this photo.

We found my 6-year-old's arm span did equal his height, and my 4-year-old was a little taller than hers.

What is the ape index?

Ape index is the ratio of arm span relative to their height. So my little boy had an ape index of 1.

An arm span greater than height is thought to be advantageous in some sports, such as swimming, as longer arms may give greater propulsion. A shorter arm span is useful for weight lifters as they don't have to lift the weight as high.

How to calculate ape index

Ape Index - Method 1

Wingspan / Height

If ape index is greater than 1, wingspan is greater than height. If ape index is less than one height is greater than wingspan.

Ape Index - Method 2

Wingspan - Height

Ape index calculated this way is either a positive or negative number.

Can you work out your ape index or arm span?

Grab the instructions below. I have a basic investigation instruction sheet and also a slightly different format using a question.

More human body science ideas

Can you work out how many feet tall you are?

Make a model of a heart or a brain model.

Or, for little ones, try some of these great preschool science ideas.

The post Is your arm span equal to your height? appeared first on Science Experiments for Kids.

Earthworms are pretty amazing creatures. To celebrate all things earthworm I've put together a list of fun earthworm facts and earthworm activities for kids!

Earthworm facts

• There are over 3000 different kinds of earthworms
• Annelids - the phylum of which Earthworms are part, are good swimmers.
• Some in Australia can grow to over 3 meters long!
• The scientific name for the common earthworm is Lumbricus terrestris.
• Earthworms have no eyes or ears but are very sensitive to vibrations.
• Worms are often eaten by hedgehogs, birds, frogs and toads.
• There are about 3 million worms per acre of grassland. That's a lot of worms.
• Fossils are rare due to their soft body.
• They tunnel underground by eating the soil.
• Worms are invertebrates. They don't have a backbone or internal skeleton.
• Earthworms feed on leaves and the remains of dead plants. With our wormery, we saw the leaves broken down and dragged into the soil.

How do earthworms move?

If you look at an earthworm, you can see its body is made up of many segments. Underneath the segments are muscles that contract and relax, allowing the worm to move.

How do earthworms breathe?

Earthworms absorb oxygen through pores in their skin, which is why they come to the surface when it rains. They also need to breathe if their burrow becomes waterlogged.

Why do we need worms?

Worms are essential for the well-being of plants. Their tunnels allow water to reach the roots, and the process of the worm-eating soil releases nutrients needed by the plants. Worms are also a source of food for other animals.

Did you know worms were such amazing creatures? For a light-hearted look at the life of a worm, we love the book, Diary of a Worm.

Earthworm Activities for Kids

We all learned a lot from making our own wormery.

If you don't fancy making your own wormery, Interplay has a great wormery kit.

For young children, make a SUPERWORM themed sensory tray.

Finally, try this fun counting worms activity from Fantastic Fun and Learning.

The post Earthworm Facts for Kids appeared first on Science Experiments for Kids.

Did you know beetles make up about 40% of insect species?

Beetles have a tough exoskeleton ( outer skeleton ) and hard forewings; like all insects, their bodies are made up of three parts: the head, thorax and abdomen. Different beetle species have different appendages, but I have kept things simple for this activity.

Build a beetle

Print out the beetle below and cut it into separate parts for each number.

The idea of the game is that all the bits start in the middle, and each player retrieves a body part depending on the number rolled on a die.

The first player to build a complete insect wins.

We also made the same game using play-doh parts.

Beetle Fun Facts

The hard exoskeleton is made of plates called sclerites.

The head - contains antennae, eyes and a mouth.

Adult beetles have two sets of wings.

Some have remarkable eyes which allow them to see above and below the waterline.

A single beetle can lay thousands of eggs in its lifetime.

Ladybirds are a kind of beetle.

Insect Extension Activities

Can you draw a picture of a beetle and remember all the body parts?

Can you find any beetles in your garden and identify the body segments with a magnifying glass?

The post Beetle Game - Introduction to insects appeared first on Science Experiments for Kids.

Valentines Day is coming up, so I thought we'd do some activities based around that, starting with some chocolate leaves. These are also a fun idea for Christmas science in the kitchen.

Mint Chocolate Leaves Ingredients

Mint leaves

Chocolate ( we used a lovely 70% dark kind )

How to make mint chocolate leaves

Melt the chocolate. You can do this in a microwave or in a bowl placed over another bowl of hot water ( take care with both methods ).

Check the chocolate isn't too hot, and then dip the leaves into it. Another way to do this is to paint the chocolate over the top of the leaves.

Place in the fridge to cool.

Gently peel the leaf away from the chocolate. What do you think?

Can you see the imprint of the leaf veins in the chocolate? Veins form part of the transport system of a plant. They carry water and nutrients to to the leaf and remove the sap from the leaf. They also help give the leaf its structure.

This experiment is a great way to demonstrate the process of changing state from solid to liquid and back again.

Everything we know exists in three states: solid, liquid or gas!

Substances  can change from one state to another by different processes.

SOLID  ––> LIQUID = MELTING

LIQUID ––> GAS = EVAPORATING/BOILING

GAS  ––> LIQUID = CONDENSING

LIQUID ––> SOLID = COOLING/FREEZING

When the chocolate was heated it changed from solid to liquid ( it melted ) then it changed back into a solid as it cooled.

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Have you ever looked up at a tree and wondered how tall it is? I've got a fun way you can find out without having to climb to the top with a tape measure!

How can you measure how tall a tree is?

We have an easy way to find out!

Why does it work?

This method of measuring the height of a tree is only an estimate but uses trigonometry. If you look at the top of a tree at a 45-degree angle, then the height of the tree (h) is the same as the distance that you are from the tree. 

More ideas for science in the forest.

Did you know you can make a weather station using pinecones?

Or how about collecting pinecones and leaves to make estimating jars?

Do you know the three different ways of working out how old a tree is?

A homemade wormery is always a fun outdoor activity, too and great for observing over a period of time.

We LOVE these cardboard nature hearts from learning through play!

You might also like my other easy science experiments for kids! I've got STEM Challenges, science fair project ideas and lots more exciting science experiments for kids of all ages.

The post How tall is a tree? appeared first on Science Experiments for Kids.

Todays preschool plant activity is very simple and is especially aimed at younger children.

We wandered around the garden looking at all the plants and flowers discussing which were big and which were little and talking about the different colours. Then we talked about what the different parts of a plant are called.

Once back inside I made some labels and asked the girls to stick the correct labels on this wooden toy plant.

Flowers are usually brightly coloured. Do you know why this is?

Why are plants brightly coloured?

Plants are brightly coloured to attract insects, which spread pollen from the flower and fertilise other flowers allowing them to make seeds.

What are leaves flat?

Leaves are flat because the leaves use sunshine to make food to grow. This process is called photosynthesis.

What happens in the stem of a plant?

The stem is like a big pipe, which takes water and nutrients to all parts of the plant. Do you remember our transpiration experiment?

We also talked about roots and how they are used by the plant to suck up nutrients and water from the soil.

The post Simple Science - Plants appeared first on Science Experiments for Kids.

The water cycle is an amazing process that we started to talk about when discussing evaporation a couple of weeks ago. In this simple science activity, children make a model of the water cycle to show the process in action.

What is the water cycle?

Water on Earth is recycled over and over again; it's always moving. This recycling process is called the water cycle.

1. Evaporation - water evaporates into the air

The sun heats water on land, rivers, lakes and seas, turning it into water vapour.

The water vapour rises into the air.

2. Condensation - water vapour condenses into clouds

As water vapour in the air cools down, it turns back into tiny drops of water. These tiny drops of water form clouds.

3. Precipitation - water falls as rain

As the amount of water vapour in the clouds increases, the clouds get heavier and heavier. If it's cold enough, water falls back to the ground as rain, sleet, or snow.

4. Water returns to the sea

As rainwater runs over the land back to rivers and the sea, some is taken up by and used by plants, and some returns to the air through transpiration. Most rainwater collects in lakes or rivers and flows back to the sea for the water cycle to start again.

The arrow from the sea to the sun - evaporation

The arrow from the sun to the clouds - condensation

The arrow from the Clouds to the mountains - precipitation

Make a water cycle model

You'll need

A plastic bowl (mixing bowl size)

Cling film

A mug

String

Water

How to make a water cycle model

It is best to do this outside in a sunny place.

1. Place the mug in the bottom of the bowl

2. Add water around the mug so that it comes up to ⅔rds of the mug—if you can draw on the bowl, mark where the water level is.

3. Cover the bowl tightly in clingfilm and fasten it in place with the string.

4. Watch what happens!

How does the water cycle model work?

You should find that you can see condensation drops of water on the top of the cling film and that the water level has lowered, proving that evaporation has taken place. The condensation droplets are the clouds. They will be dripping back into the bowl, but you should find some water in the cup (your mountains), demonstrating precipitation!

More Water Cycle Activities

Can you make a water cycle in a bag? Draw the sun and a cloud on a bag. Add some water and stick it to the inside of a sunny window. Watch as the water evaporates and condenses inside the bag!

Water Cycle Worksheet

Print the water cycle diagram below, cut out the squares and stick them in the correct place!

We love the LEGO water cycle model from EDventures, and the raining sponge from The Pinterested Parent is brilliant!

Did you know you can measure rainfall with a simple rain gauge?

Don't forget to try my other weather science experiments, too!

The post Easy Mini Water Cycle Model appeared first on Science Experiments for Kids.

A few weeks ago, when we had a brief hot spell, we added water to some sand and left it outside to see what would happen. This activity is a great, easy way to learn about evaporation, the water cycle and changes of state too!

Evaporation and the Water Cycle

Within 36 hours, the water had disappeared!

How can you separate sand and water?

The water evaporated because of the heat from the sun. Evaporation is when a liquid vaporises.

Many factors affect evaporation, but the main driving force is solar energy from the sun.

Make it an experiment!

If you wanted to set this up as an experiment or investigation, one way to set it up is to leave the wet sand in different places ( sun, shade, indoors etc.) and observe how the sand in each area changes over a period of time.

Evaporation is an important part of the water cycle

Condensation - this is when a gas turns back into a liquid. The water vapour in the air gets cold and turns back into a liquid to form clouds.

Precipitation is when so much water condenses that the clouds get heavy, and water falls back to earth as rain ( or snow ).

Collection - this is when rain collects in rivers and oceans, and the cycle starts again.

Try pouring a cold drink into a glass on a hot day, and watch what happens on the side of the glass. What do you think this is an example of?

More water cycle experiments for kids

Make a Mini Water Cycle with a bowl, cup, water and clingfilm.

Learn about The Water Cycle and Flooding.

We've also got a fun collection of weather science experiments for kids, including a rain gauge, barometer and storm in a jar!

The post Evaporation and the Water Cycle appeared first on Science Experiments for Kids.

If we want to grow a plant, we usually do this by planting a seed. The seed is produced by sexual reproduction (two parents), meaning that the egg from one plant and the pollen from another have met and formed a seed, resulting in the plant having qualities from both its parent plants.

However, what if you had a most beautiful plant with the prettiest colour flowers and you wanted to ensure that another plant had that colour flower - what could you do?

Clone them?

Not as silly as you might think.

Tissue cuttings are the simplest way to produce a cloned or identical plant.

How to clone a plant

What you need

• compost
• small plant pot
• small plant trays
• an original/parent plant ( we used geraniums)
• rooting powder or gel

Instructions

1. Take a healthy plant (I used geraniums) and cut a small length from the stem

2. Place this in water for a few minutes

3. Dip the end into rooting powder or gel

4. Pot the plant up with some lovely compost

5. Keep the pot away from direct sunlight and cover it in a clear plastic bag to keep it moist.

Your cutting will now grow into another plant exactly the same as your original!

You then need to nurture them, like any parent would!

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We've talked about respiration before when we made bread and used yeast to make the dough rise. Blowing up a balloon with yeast is another very easy experiment to demonstrate respiration in action and is quicker than making bread if you are short of time.

What is respiration?

Respiration is a chemical reaction which occurs in animal and plant cells. It releases energy from glucose. Aerobic respiration needs oxygen, but anaerobic respiration doesn't need oxygen.

Anaerobic respiration produces less energy than aerobic respiration. It occurs in humans when not enough oxygen reaches muscle cells ( for example, during hard exercise ). Bacteria and other microorganisms can also use anaerobic respiration, and yeast actually carry out an anaerobic process called fermentation.

Respiration occurs in the mitochondria of cells. You can find out more about mitochondria by making a model of a cell.

Blow up a balloon with yeast

A balloon

A small clear drinks bottle

A packet of dried yeast

Warm water

1 teaspoon of sugar

Instructions

1. Blow the balloon up a few times to give it some stretch. This just makes it easier for the experiment to work.

2. Fill the small bottle about 3cm full of warm water.

3. Add the yeast and 1 teaspoon of sugar.

4. Place the balloon over the open top so no air can escape.

5 Over the next half an hour, watch what happens. (Obviously, do other stuff and come back, it may be a little boring to actually watch it for half an hour!)

Yeast and Respiration

Yeast is a living organism. In order for it to survive, it needs to make energy. In its dried form, the yeast is dormant, but as soon as you provide it with warmth, water and sugar (its food), it 'wakens' and becomes active. The yeast uses the sugar (glucose) and oxygen from the bottle to make water, energy and carbon dioxide. Carbon dioxide is a gas, and this is what you see filling the balloon.

Remember, yeast can respire anaerobically when there's not enough oxygen for aerobic respiration.

Fermentation

Glucose -> ethanol and carbon dioxide + energy

Aerobic Respiration Equation

Glucose + Oxygen --> Carbon Dioxide + Water + energy

The image is taken from Snackable Science which contains SEVENTY fun edible experiments and investigations!

Science concepts

Enzymes

Respiration

Contains affiliate links

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Looking at food groups is such a fun thing to do. It gives children a real insight into the types of food they eat, and you can use it as an opportunity for taste testing.

For younger children, you can introduce food groups in terms of what they are: There are five basic groups.

Then on an old plate or paper plate, divide it into five with a whiteboard pen board pen and label as the groups - this will easily wash off, and using the sheets below cut out the foods and add them to the plate portion you think they belong too.

Food groups work sheet

You can then ask your child which ones they would like to try and maybe plan a trip to the shop to purchase and hold a little tasting session.

Moving forward with older children, you can then introduce the nutrient food groups.

There are seven basic nutrient food groups. These include:

Each group is needed by the body for different reasons and can be found in different types of foods.

I have included this table for you to use in a sheet below.

Food groups Table

Food Group Activity

Take an empty muffin tin, and in each of segment put a different type of food.

Make some flags using cocktail sticks and paper and label each one with a letter to represent the food group.

Discuss each food describing how it looks and maybe taste it to see if that gives any clues - is it rich or grainy or smooth like dairy? Then stick a flag into the food that it belongs to!

Finally, you could then print out the table above, chop it up and use it as a card for a revision exercise.

Have Fun

Kerry

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Every time we go for a walk at the moment, my children look for dandelions with a full seed head to pick and then blow so they can watch all the tiny parachutes float away in the wind. We started talking about why they fly so well and their purpose. This is also a fun way to find out about air resistance.

We decided to try to make our own parachutes

How to make a dandelion parachute

You'll need

Paper

Scissors

Sellotape

Optional paperclip

Instructions

Cut an A4 piece of paper lengthways in half so you have two long strips of paper.  Roll each into a tube and stick it in place with sticky tape.  Drop the tubes from somewhere high.  You could try to time their fall (or just note it)

Now use the scissors to cut down the tube in several places. (We gave one tube wide flaps and one very thin flaps.)

Drop the tubes from somewhere high and watch them fall. Does one fall faster than the other? You could also compare the speed of a tube with no flaps falling from the same height.

You can add a paperclip to the bottom to add some weight, but this is not necessary.

How does a dandelion parachute work?

When a dandelion has finished flowering, the flower head dries out, and the parachute ball opens into a full sphere. Eventually, the seed-bearing parachutes expand and are released. The seed drops off the parachute when it hits the ground or another object.

In our models, we were able to make the paper tubes stay in the air longer by providing flaps which offer more air resistance.  This gives them the opportunity to float further away from where they were released.  With dandelion seeds, this means they can spread out further from the main plant, meaning they can populate wider areas than if they just dropped straight off the plant.

Have a look at other ways plants disperse their seeds.  We did notice our models spun as they fell to earth, which reminded us of sycamore seeds.

More dandelion and seed dispersal activities

Find out what happens to a dandelion in water.

Make spinning helicopters like a sycamore seed.

The post Dandelion Parachutes appeared first on Science Experiments for Kids.

Choice chambers are an investigative method used to study animal behaviour and to determine the favoured conditions for a habitat.

It is a very simple investigation to set up, and one that kids love as it involves searching for insects and then predicting and watching.

The living organisms that we chose to study were woodlice, as they are easy to find.

We decided to investigate whether woodlice

• prefer damp or dry conditions
• dark or light conditions

You will need:

A minimum of 5 woodlice

A collection pot

Two dishes with  lids

Filter paper (I just used coffee filter paper)

Dark or black paper

A pen/scissors

Method

1. In your collection pot, put in some soil and dried leaves. Start looking under stones and bricks for some woodlice and put them in the pot. Make sure it is deep, as woodlice are very good climbers, and we had a few escapees! This is just to keep them happy when not under investigation, as we do not want to put them under undue stress.

2. Draw around the lid of your pot onto the filter paper

3. Cut it out and fold it in half.

4. Wet it and place it on one side of the pot.

5. Add your woodlice and, over time, see which side they prefer over time (about 5 minutes to let them acclimatise to their surroundings). The side that has the most woodlice is the side they prefer.

6. You can then repeat this experiment using dark paper to block out one side of the lid to see whether they prefer dark or light conditions.

7. You could also see if you can carry this out with other insects.

Please be sure to return the insects to the place you found them.

Have Fun

Kerry

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It is always tricky to get children to understand that living things can get eaten by other living things. We have tried very hard to make sure my children know that a chicken in a packet was once a live chicken and that they are food for us.

So with that in mind, we decided to look at food chains.

We got out all of the children's plastic animals and a few soft toy animals (ones that were missing) to help. We also picked some leaves from the garden, and I made some red arrows on the computer and printed them out.

Firstly we names all the animals to check he knew what they were.

We then group the animals into

1. Meat eaters (Carnivores)

2. Vegetable Eaters (Herbivores)

3. Both (Omnivores)

Then we decided if we could make some chains with arrows to show what was eaten by which animal. The arrow in a food chain means 'Food for'.

I explain that all food chains usually start with a 'producer' or, as I explained to Noah, a vegetable or something green as it makes its own food from the sun.

Then anything that eats something else is called a consumer.

These are some of the chains we made!

This is such a simple exercise for little ones, but if you want to stretch older children t that bit further, then I have made the worksheet below. It contains cards to cut out and arrows so you can make your own food chains and a vocabulary sheet. I have included the answers for the chains on the fourth sheet.

Simple Food Chains 1

Have fun with your food chain exploration!

Find out more about food chains and food webs.

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Here at Science Sparks, we love experiments using eggs. Eggs are generally inexpensive and can usually be eaten before or after the activity, so there's no waste.

These are my five favourite Egg Experiments.

Five Eggy Experiments

Make an eggshell disappear

Make an eggshell disappear! This is like magic! Watch the shell of an egg disappear before your eyes. Just be careful not to break the membrane.

Make an egg shrink

Learn about osmosis by making an egg shrink! You'll need to remove the shell to expose the delicate membrane.

Eggshell bridge

Find out how strong an eggshell is by making an eggshell bridge! The dome shape is surprisingly strong.

Drop an egg into a jar

Learn about air pressure with a boiled egg. The change in pressure between the outside and inside of the jar pulls the egg into the jar.

Which is your favourite Egg Experiment?

If you liked these, don't forget to take a look at my full collection of eggy experiments.

The post Five Excellent Egg Experiments appeared first on Science Experiments for Kids.

Why does food rot? Have you ever noticed that if you leave an apple (or any fruit ) for too long, it starts to rot or decay? This can lead to a lot of food waste, so it's important to understand how to store food items so they last as long as possible.

Why does food rot?

Food rots because micro-organisms such as bacteria, yeasts and fungi feed on the fruit and break it down. Have you also noticed that keeping fruit and vegetables in a fridge makes them last longer? This is because the cold slows down the growth and reproduction of microorganisms, slowing their decay.

How to preserve apples

This simple science activity investigates ways to stop apples from spoiling without a fridge!

What you need for an apple rotting experiment

• One apple
• 4 containers
• lemon juice
• vinegar
• salt water ( 1 tablespoon salt dissolved in hot water )

Apple rotting investigation instructions

• Cut the apple into 4 even pieces.
• Place a segment of apple into each container.
• Cover each apple with the same amount of either lemon juice, vinegar or salt water. Leave one just exposed to the air     ( this is the control ).
• Leave untouched for about a week in a cool place and observe the differences.

Apple rotting investigation results

Control Apple - you can see this has started to shrivel up, but there is not much evidence of mould.

Apples preserved with salt and vinegar ( vinegar is at the front )

Apples preserved with lemon juice

How can you stop food from rotting?

There are many mechanisms for preserving food. All slow or stop the activity of micro-organisms which make the food decay.

As well as refrigeration, you can freeze, can or pickle foods to preserve them.

You can see from the photos that in our investigation, the apple segment in the salt is the best preserved. This is because salt draws the moisture out of the food, so the micro-organisms do not thrive and cannot reproduce as fast as they can in other conditions.

The vinegar did prevent mould growth. This is because vinegar has anti-microbial properties. It inhibits or kills the microorganisms that lead to mould on the surface.

You can see that the lemon juice shows evidence of mould. This could be because the micro-organisms have flourished in the sugary environment.

More food preservation ideas

Can you think of other things to try? What about bicarbonate of soda? Or other fruits?

The Free Range Life has some great ideas for preserving peppers you could test too!

More kitchen science experiments for kids

These egg experiments are fantastic fun!

Find out how to transform egg white into beautiful meringue!

Make your own rock candy!

Or, go all out and have a Science Bake OFF!!

The post Why Does Food Rot? appeared first on Science Experiments for Kids.

This is a brilliant investigation for finding out how waterproof different materials are.

I printed a picture of a chicken and asked the children to colour it in, then gave them a selection of materials to protect the chicken from water.

What you need

• Paper with a picture on it.
• Materials such as kitchen roll, plastic, bubble wrap, and greaseproof paper cut into squares.
• Water
• Glue

Instructions

Place the squares of material over the picture.

Sprinkle water over the picture and see which types of material repel the water the most. Z put several layers on his after realising his first layer wasn't going to be waterproof enough. He was very proud when his chicken stayed dry, though.

Afterwards, we talked about how the waterproof materials felt different to the others. Z said they were shinier and harder to break.

Can you think of anything else you can waterproof?

The Science Bit

Waterproof objects cannot be penetrated by water. Rubber and wax are examples of natural waterproof coatings that are often used to make materials waterproof.

Can you think of any more waterproof materials? Is your coat waterproof? What's it made of?

 Suitable for Key Stage 1

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The transformation from Caterpillar to butterfly is one that hooks in children, however old they are.

We are big fans of the Hungry Caterpillar by Eric Carle in this house, and it is a great way to introduce the lifecycle of a caterpillar.

Firstly we read the story.

Then we talked about a cocoon and what it must be like to be all wrapped and snuggled up. We attempted to make our own cocoon around Noah, and the twins in toilet paper, and they burst out of it from the top! They loved this game!

We then decided to make some caterpillars.

You will need:

An egg box

Paints

Pipe Cleaners

Marker pens

Googly eyes

Cut an egg box so that you have a strip of the carton.

Paint it green (as I thought) or red as Noah did and yellow as Little Madam did!

In each section, put a hole on each side and thread through a pipe cleaner for the legs.

Use some pipe cleaners as antennae.

Put on the googly eyes!

Place on some cutout leaves!

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Your brain is made up of billions of specialised cells called neurones that transmit information by chemical and electrical signals. They control every thing we do, right down to how we feel - our emotions.

It is thought an area on the side of the brain called the amygdala controls how we feel - excited to open a present, sad when someone breaks a toy, or angry at unfairness.

Noah is a very emotive little boy and is very aware of other people's feelings. he constantly asks me if I am happy, or sad. When he is confused he will say 'what face is that?' to me.

So Firstly I asked him to show me his faces for angry, sad and happy. This was his interpretation.

We then decided to see if he could interpret some other faces.

I cut out lots of faces from magazines and newspapers throughout the week.

I made three prints out with happy, sad and angry on them (and because he can't yet read- he is only three!) I put faces that matched the emotion on them too.

We then went through each cut out picture and place it on the poster he thought it most matched.

We then glued them all down.

You could extend this further with other emotions for older children or get them to decide the emotions first hand.

It is also a great way to get little ones to communicate and understand how they feel.

The post Fun Sparks - Emotion Posters appeared first on Science Experiments for Kids.

The brain is one of the most fascinating organs, so today, we're going to make a model brain.

The brain is the control centre of your body, and it sits in your skull at the top of your spinal cord. When we mention the word 'neuroscience,' most people switch off and think it is something they cannot possibly understand but...

1. Not when you get to play with play-dough (this keeps me and children of all ages entertained)

2. It is really, REALLY interesting!

Some interesting facts!

Your brain keeps on growing until you are about 20 years old.

Your brain has around 100 billion nerve cells

Your brain is more powerful, more complex and more clever than any computer ever built.

It is constantly dealing with hundreds of messages from the world around you and from your body and telling your body what to do.

With evolution, the human brain has become more and more complicated, and many of its interesting properties are still not well understood by scientists.

The human brain is over three times as big as the brain of other mammals that are of similar body size.

The brain can be divided up into six main areas:

The frontal lobe  (Green)

• reasoning, planning, parts of speech and movement, emotions, and problem-solving

The Parietal lobe (purple)

• Senses touch, pressure, temperature and pain.

The Occipital Lobe (yellow)

• Controls vision

The Temporal lobe (blue)

• Recognition of hearing and memory

The Cerebellum  (brown)

• Controls and coordinates movements of the muscles

The Brain stem (Pink) 

• In charge of keeping the automatic systems of your body working, like breathing! 

Make a model brain using six different colour play-doughs

You can then make some flag labels (wrap stickers around cocktail sticks) and label the brain.

I made this with Noah (who is three) and was really interested in finding out that the brain helps you think, talk, see and move and that it is inside your head. He understood there were six parts, in which we practised counting, and named all the colours, but obviously, the names of the parts were a little advanced, however, I know my secondary school pupils would have loved this task and in fact, even my A level students who are 18! Well, who doesn't love play-dough?

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Yeast is a living single celled organism commonly used in baking. Yeast is a type of leavener ( baking soda and baking powder can also be used as leavening agents ). Yeast converts 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. Yeast works best in a warm, moist environment, which is why it's best to leave the dough somewhere warm to rise. This conversion of sugar into carbon dioxide and ethanol is called anaerobic respiration.

We can see respiration occurring in yeast when we make bread or pizza dough.

Note - respiration in yeast is anaerobic respiration - this means it doesn't use oxygen

Pizza Dough Respiration Investigation

Pizza dough ingredients

500g Strong White Flour

7g Yeast (Fast)

1tbsp caster sugar

330ml Luke warm water

1 tsp salt

1tbsp olive oil

How to make pizza dough

• Mix the yeast, sugar and water in a jug and put to one side.
• Sieve the flour into a mixing bowl and add a pinch of salt.
• Gradually add the water until a nice elastic dough is formed.
• Knead the dough well, strong flour will take a lot of effort to get nice and elastic, so work it hard.

Leave it somewhere warm, we left ours in the airing cupboard for about an hour. Look how much it increased in size.

Once risen, knead the air out of the dough again and roll it out to make your pizza bases.

We turned our pizza into a plant cell model. The green peppers are chloroplasts!

More Yeast Experiments

Did you know you can use the power of yeast to blow up a balloon? First blow up the balloon and let the air out. Pour a packet of yeast, warm water and a tablespoon of sugar into a small bottle and quickly pop the balloon on top. Give the mixture a shake and you should find the balloon blows up thanks to the carbon dioxide gas produced by the yeast.

The post What is Yeast? appeared first on Science Experiments for Kids.

I love a good cup of tea. In fact, I cannot actually function without one first thing in the morning. If you're like me, then this investigation is definitely needed in your house so that you can ensure your kids are equipped with the best tea-making skills and have the best scientific knowledge to back up what makes a good cup of tea! This investigation looks at diffusion through the partially permeable membrane of a tea bag.

So firstly, we want to know what type of teabag makes the best drink?

Is it a square, a pyramid or a circle bag?

The activity involves using hot water, so adult supervision is essential.

Teabag diffusion

You'll need

A stopwatch/timer

A piece of white paper

A pen

3 clear glass mugs (you are going to add hot water, so not thin ones that could crack)

Circle, triangle and pyramid tea bags

Thermometer or kettle

Method

1. On the piece of white paper, draw a cross with a marker pen

2. Place one mug over the cross

3. Add the circle teabag

4. Boil water from the kettle and measure out 150ml (if you have a thermometer, you can improve reliability by keeping the temperature constant)

5. Pour over the teabag and start the stopwatch

6. Time how long it takes for the cross to disappear

7. Repeat with the pyramid and square teabag.

8. To make the investigation results more accurate, repeat with each teabag three times.

Record your results in a table

How does the tea diffuse into the water?

So which teabag was quicker?

You should find that the pyramid teabag was the quickest.

Why do you think this is?

As the water is added to the teabag, it causes the tea leaves to move and triggers diffusion of the leaves. Diffusion is defined as the movement of a substance from an area of higher concentration to an area of lower concentration. There are lots of tea molecules in the bag and none outside. The leaves themselves can't pass through the bag, but their smaller particles containing colour and flavour can (the teabag itself acts as the partially permeable membrane). The addition of heat (from the hot water) to the tea bag causes its molecules to move much faster than at room temperature. This energy is more readily released in a shorter period of time than a tea bag filled with room temperature or cold water. The teabag shape affects the surface area and the pyramid due to its 3D shape providing more surface area for diffusion to take place and more area in the middle for the tea molecules to move around in spreading the colour and flavour.

Ok, so now they know which is the best teabag to use and how to let it brew...so I suggest you ask for a nice cuppa now!

The post Tea bag diffusion! appeared first on Science Experiments for Kids.

Winter can be a tough time for birds. Whilst we are tucked up under our blankets drinking hot chocolate, birds are out there facing the harsh conditions of winter. Although many stay in this country the hardened cold weather can put them at risk. Food is in shorter supply and if an ice frost creeps over it can harden nuts and berries and make it impossible to eat them. Birds can starve to death after three days if a frost or snow continues and many rely on bird feeders as their only source of food.

Make food in high fat contact helps as they are then able to store up reserves.

It is important to remember that if you start putting food out, you need to commit to it as birds start to become reliant on where their food source is.

So I am going to show a really simple way to make Bird Feeders with you little ones...or in fact big kids (including me) love this too!

Pine Cone Feeders

What you need:

Pine cones

Butter/lard

Good quality bird seed.

Method

Firstly you need to find some pine cone, which require a nice little nature walk

Pour some bird seed into a tray or pot.

If you intend to hand the pine cone tie some sting around the bottom, if not you can leave this bit out.

Using the butter or lard, take off lumps and smear into the crevices of the pine cone

Once saturated in butter, roll the pine cones in seeds.

Take out to your new bird feeders to your bird table!

You could even make them with peanut butter, which is also high in fat.

Have Fun

Kerry

Multiple Mummy

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Respiration is a fundamental biological process. It is the process by which energy is made so that all the chemical reactions can occur in your body.

Respiration is the reaction between glucose (from food) and oxygen in the air you breathe to produce carbon dioxide and water (waste products) and the all-important ENERGY!

We can see this process occurring when we make bread!

You'll need

A mixing bowl

500g of strong white bread flour

2tsp of salt

Two sachets of yeast

40g of soft butter

300ml of tepid water

Olive oil

Respiration demonstration - bread making

1. Put the flour in the bowl along with the chopped-up butter.

2. Put the salt on one side of the bowl and the yeast on the other (otherwise, the salt will kill the yeast)

3. Mix and add the water slowly to bring together a rough dough

4. Put a tsp of olive oil onto the work surface and put your dough on top.

5. Start kneading together the dough so it is coated in the oil and becomes smooth and stretchy. This may take at least 5 minutes.

6. Clean out your mixing bowl and smear with oil

7. Place your dough into the bowl and cover it with a damp tea towel

8. After an hour, it should have doubled in size.

9. Tip the dough onto the work surface with some flour, knead out the air until smooth, and roll into your loaf shape.

10. Place on a lined baking tray and cover with the tea towel again to rise one more.

11. After another hour, it should have doubled in size.

12. Sprinkle on some flour and score in your pattern.

13. Place in the oven at 200 degrees with a roasting tin of water to make steam.

14. Cook for half an hour, and your bread is ready!

Why does bread dough rise?

Yeast is a living organism and needs to respire to make energy! As it respires, it produces carbon dioxide as a waste product. It is this gas that causes the bread dough to rise! Respiration in action!

Even if I say so myself, the bread is very yummy, so not only a bit of science but lunch too!

The post Making Bread - Respiration in action! appeared first on Science Experiments for Kids.

It's Autumn here in the UK and the leaves are beginning to fall and go crisp under your feet. The trees are a variety of colours and there are seeds galore. It is the perfect time to get out and about and collect things like acorns, conkers, leaves, twigs, and feathers.

Which is exactly what we did this week...and we collected an array of things including a lot of stones!

So we brought them all home and started talking about what animals do with the things that have fallen from the trees. I explained that some store them up as food for the winter, some build nests and homes, and some used them to hibernate.

'What's hibernate?' Noah asked

I explained it was sleeping through the winter although this is not strictly a good description and I shall explain more in a bit. I told him that only three animals do it in the UK, hedgehogs, bats and dormice.

Hedgehogs hibernate because their food source (insects) become in very short supply during the winter months from either dying or going into hiding. This makes the hedgehog vulnerable to weight loss and it is during these months when it would actually need more food in order to keep it warm.

Going back to the sleep part - during sleep all bodily functions remain working. During hibernation the hedgehogs metabolism almost shuts down. It heart rate drops from 190 beats per minute to 20 beats per minute and all his extremities appear cold to the touch. It could easily be mistaken for dead.

Hedgehogs will not hibernate until there is no sign of food left so you can still see hedgehogs about until as late as January some years, but most start making their hibernation nests during Autumn and building up their fat reserves ready for hibernation during November and December. They come out of hibernation at spring time when the temperature begins to rise. They immediately stock up on on food, not only to replenish lost body mass but just in case there is another frost and they resort back into hibernation.

So with hedgehgs on out minds we set about a hedgehog craft activity and it is really easy!

What you need:

Paper

Pens

Leaves

Glue

1. Collect your leaves

2. Draw a rough outline of a hedgehog onto the paper

3. Stick on the leaves starting from the back and sticking up as prickles and layer it with more leaves as you move towards the face.

The result is a very gluey (if you have a 3 year old like mine who is a little generous with the glue) autumnal hedgehog picture.

The post A prickly craft with Hedgehogs! appeared first on Science Experiments for Kids.

Welcome to a very eggy week on Science Sparks! Shrinking eggs is the first of 3 egg based experiments, so if you like this one, pop back later in the week to see what else we have been up to! This experiment looks at osmosis.

Osmosis is the net movement of water molecules across a partially permeable membrane from a region of higher water concentration to a region of lower water concentration.

Water molecules flow from one side of a membrane to the other until the concentration of water molecules on both sides is equal.

What you need:

• Two eggs
• Water
• Two glasses
• Vinegar
• Sugar
• A pin

This experiment has 3 stages:

Remove the shell from the egg with vinegar

Shrink the egg by placing it into a concentrated sugar solution

Grow the egg by placing it in water.

Remove the shell from an egg

We need to remove the shell to expose the semi-permeable membrane of the egg. This can be done by placing the eggs in a cup of vinegar, so they are totally covered for about 24 hours. After this time wash the egg rubbing away the remaining bits of the shell.

Shrink and grow the egg

Make up a concentrated sugar solution by dissolving sugar in water. Place one egg in a glass of water, and the other in the sugar solution. Our sugar solution looks quite dark as I used brown sugar. Note how the egg in the water sinks to the bottom of the glass while the one in the sugar solution floats. This is because the sugar solution is denser than the water.

• Leave for another 24 hours. You can see the egg in the sugar solution looks much smaller than the one in the water.

Prick the egg from the water with a fine needle and watch a jet of water shoot out!

• Put the shrunken egg in water and watch it grow as it reabsorbs the water, this might take a few hours.

Why does the egg shrink and grow?

The sugar solution is much more concentrated than the water, this is because it contains dissolved molecules of sugar. The dissolved sugar molecules cannot pass through the semi-permeable membrane of the egg, but the small water molecules can. The water moves from the less concentrated egg solution to the more concentrated sugar solution until the concentration of water is the same on both sides. Therefore water moves from the egg to the sugar solution, and the egg shrinks.

When the shrunken egg is placed back in water, the concentration of water inside the egg is lower than the water, so water moves from the water to the egg, making the egg increase in size.

When we pricked the egg that had been in the water, water shot out of the egg. This is because the egg has absorbed water, and so the inside of the egg is under more pressure than usual.

The egg shell dissolves in the vinegar as the acetic acid in the vinegar reacts with the calcium carbonate of the shell. Carbon dioxide is given off during this reaction so you should see bubbles of gas escaping.

Extension Tasks

Weigh the eggs after removing the shell, after they shrink and again after they reabsorb water to see how much water is lost and gained at each stage.

Try adding food colouring to the water and watch as the eggs absorb the coloured water.

Soak a boiled egg in vinegar, this should make the egg so rubbery it will bounce ( from a low height ). You can also bounce a non-boiled egg that has been soaked in vinegar.

Don't forget to wash your hands after handling raw eggs!

The post Osmosis and Shrinking Eggs! appeared first on Science Experiments for Kids.

So today we came up with this idea. We would go on a nature trail…outdoors but in our own back garden, and we would stick our findings to a piece of cardboard that we had covered in double sided glue spots. I would have braved going down the trail at the back of house that leads to the park, but I just didn’t have the mindset to stomach the disgruntled looks of other parents, staring at my grotspots as if we have the plague.

So our trek began… (a bit like Winne the Pooh and Piglet on their search for heffalumps!) It was beneficial doing it in the garden because we don’t have a dog, so avoided Noah’s obsession with looking for dog poo and despite it being a complete mess (ignore any laundry, weeds or things we are trying to sell that may be in pictures) it does have some interesting things and a little bit of colour

So here is our piece of card (cut from a good old Cheerios’s box, covered in sticky dots.

First we stuck on some petals (from my beautiful roses – struck down in their prime due to keeping a 3 year old entertained!)

Then some leaves and obviously he had to taken a photo of his own masterpiece!

A little bit of grass…obviously! (I did have to try and explain why ants could not be stuck to his creation!)
Voila! Master piece is finished…although he does not look convinced! Maybe tweak it later!

Voila! Master piece is finished…although he does not look convinced! Maybe tweak it later!

There you have it, some easy craft, nature, science, play and the outdoors all in the comfort of your back garden. You could go further afield if you are not spot infected like we were!
Give it a go

Have fun!

The post An outdoor craft adventure! appeared first on Science Experiments for Kids.

Whether you love them or loathe them, spiders are hugely essential creatures. Without spiders, there would be a LOT more insects eating our crops, which would seriously affect our food supply.

Spiders are invertebrates ( they have no backbone ). The biggest group of invertebrates are arthropods, including spiders. Arthropods are further subdivided into other groups, including arachnids and insects. Spiders are arachnids!

Fun Spider Facts

• Spiders are a group of animals called arachnids! Arachnids have two body parts ( cephalothorax and abdomen ) and eight legs.
• Spiders are predators, which means they hunt living prey
• Spiders will eat other spiders.
• The world's heaviest spider is the goliath birdeater, which, despite its name, eats mostly worms.
• Redback spiders use venom to paralyse small prey.
• Female redback spiders are known for eating the male after mating!
• Spiders produce silk with their spinnerets.
• The oldest spider fossils are more than 300 million years old.
• All spiders have venom, but only a very small number are harmful to humans.
• When spiders hang on their silk like a rope, it is called a 'dragline.'
• Some large spiders will trap and eat birds, bats, mice, fish and even snakes!
• Spiders are very important for controlling insect populations.
• Spiders inject their prey with digestive juices and then suck the food.
• Not all spiders have eight eyes.
• Fear of spiders is called arachnophobia.
• The fishing spider can catch fish!!

Super Spider Science - make your own sticky spider web

This very simple science activity illustrates how insects stick to spider webs. Spiders produce a sticky substance, so their prey gets stuck in the web. We can't make a web like a spider, but we can make our own version.

This is a great activity for learning about how different materials have different properties and starting to understand a spider's place in food chains.

You'll need

Hula hoop

Different types of sticky tape - duct tape, sellotape, masking tape

Small light items such as pom poms, strips of wool and ribbon, small plastic insects

Instructions

Stretch two or three different types of tape across the hula hoop and fix them securely in place.

Gently throw small items towards the web and record how well they stick on each type of tape.

Was the stickiest tape the one you expected?

More spider themed science activities

Find a way to keep Incy wincy spider dry by making a mini umbrella from waterproof materials.

Play a build a beetle game to learn more about insects.

Research a food chain featuring spiders.

Read about terrifying spider records with Guiness World Records.

The post Super Spider Facts and a Sticky Web Science Activity appeared first on Science Experiments for Kids.