Year 3 Science: Leaves: catching light and making food
Part of the Year 3 Science parts of a flowering plant chapter. Chapter overview · whole chapter on one page
Leaves: catching light and making food
Leaves are usually wide and flat. This shape helps them to catch light.
Leaves use light, water and air to make food for the plant. The food made in the leaves moves through the stem to the other parts of the plant.
Without light, the leaves cannot make food. A plant kept in a dark place cannot make food from light.
Key ideas
- Leaves are usually wide and flat, so that they can catch light.
- Leaves use light, water and air to make food for the plant.
- Food moves from the leaves to the rest of the plant through the stem.
- Without light, leaves cannot make food.
Method. Think about the surface that faces the light.
- Read the first shape. A wide, flat leaf has a large surface facing the light.large surface
- Read the second shape. A thin, straight stalk has only a small surface facing the light.small surface
- Compare them. The wide, flat shape catches more light.more light
- Write the answer. a wide, flat leaf
Check. More surface means more light is caught. ✓
Watch out. Wide and flat is the shape that helps leaves catch light.
Method. Think about what leaves need to make food.
- Think about the light. Leaves use light to make food.light needed
- Check the cupboard. There is no light in a dark cupboard.no light
- Decide. So the leaves cannot make food from light in the cupboard.no
- Write the answer. no
Check. The leaves need light to make food. ✓
Method. Think about what the leaves produce for the plant.
- Read the question. It asks what leaves make with light, water and air.make with light
- Think about the plant. The plant needs food to grow and stay healthy, and the leaves provide it.food for the plant
- Write the word. Leaves use light, water and air to make food.food
- Write the answer. food
Check. Leaves are the food-makers of the plant. ✓
Watch out
Watch out: leaves do not take in food from the soil. The roots take in water and minerals. The leaves make food, using light.
Try it at home or school (with a grown-up). Ask a grown-up to help you find a leaf that has fallen from a tree. Hold it up to a window and look at the light coming through it. Draw the leaf, and write one word to describe how much light gets through. Wash your hands afterwards.
Exam tip
Grown-up tip. Ask: “Where does the plant get its food? Why is the leaf flat? What would happen in a dark cupboard?”
Exercise 2D Leaves: catching light and making food
Method. Look at each thing and decide whether leaves use it.
- Read water. Leaves use water to make food.water: used
- Read light. Leaves use light to make food.light: used
- Read stones. Stones are not used by leaves to make food.stones: not used
- Write the answer. stones
Check. Water and light are used, and stones are not. ✓
Method. Think about the shape that catches the most light.
- Read the sentence. Leaves are usually wide and flat.wide and flat
- Find the missing word. The missing word is flat.flat
- Write the answer. flat
Check. A flat leaf is wide and thin, so it catches light. ✓
Method. Think about the path between the leaves and the roots.
- Think about the leaves. Food is made in the leaves.leaves make food
- Name the path. The stem carries the food to the other parts of the plant.stem
- Write the answer. stem
Check. The food travels through the stem. ✓
Method. Find the broad, flat parts that grow out of the stem.
- Find the leaves. The leaves are the broad, flat parts on the stem.broad and flat
- Read the letter. The letter B points to a leaf.B
- Write the answer. B
Check. The letter B is on a leaf. ✓
Method. Think about what leaves make.
- Read the sentence. Leaves make food for the plant.food
- Write the answer. food
Check. Leaves are the food-makers. ✓
Method. Think about what the leaves catch.
- Read the sentence. Leaves use light to make food.light
- Write the answer. light
Check. Light is needed to make food. ✓
Method. Think about the part the food travels through.
- Read the sentence. Food is carried through the stem to other parts.stem
- Write the answer. stem
Check. The stem carries the food. ✓
Method. Add the leaves on each side of the stem.
- Read the two numbers. There are 10 leaves on one side and 6 leaves on the other.10 and 6
- Add them together. Adding the two sides gives the total number of leaves.10 + 6 = 16
- Write the answer. 16 leaves
Check. 6 + 10 = 16, the same as the total. ✓
Method. Think about how much light the leaf catches.
- Compare the light. The leaf in shade gets less light.less light
- Decide. With less light, the leaf makes food more slowly, so the answer is no.more slowly
- Write the answer. no
Check. Less light means less food is made. ✓
| Leaf | Length (cm) |
|---|---|
| Leaf A | 8 |
| Leaf B | 5 |
| Leaf C | 11 |
Method. Find the biggest number in the length column.
- Read the lengths. The lengths are 8 cm, 5 cm and 11 cm.8, 5, 11
- Find the biggest. The biggest length is 11 cm, which is Leaf C.11 cm is the biggest
- Write the answer. Leaf C
Check. 11 cm is more than 8 cm and 5 cm. ✓
Method. Predict what happens when fewer leaves catch light.
- Think about the leaves covered. The covered leaves cannot catch the light.covered, no light
- Predict. With fewer leaves catching light, less food is made, so the answer is yes.less food
- Write the answer. yes
Check. This is a prediction. We would test it by measuring. ✓
Method. Think about what leaves need to make food.
- Think about the light. Leaves use light to make food.light
- Decide. So leaves do not make food in the dark. The statement is false.false
- Write the answer. false
Check. Without light, leaves cannot make food. ✓
Method. Think about where food is made in the plant.
- Think about the leaves. The leaves are the parts that catch light and make food.leaves make food
- Give the reason. With no leaves, the plant has no place to catch light and make food.no leaves, no food
- Write the answer. Accept any sentence that says the leaves make the food, so without leaves the plant has no place to make food from light.
Check. The leaves are where the food is made. ✓