Year 3 Science: The parts working together
Part of the Year 3 Science parts of a flowering plant chapter. Chapter overview · whole chapter on one page
The parts working together
All the main parts of a plant work together. If one part cannot do its job, the whole plant may not grow well.
| Part | Main job |
|---|---|
| Roots | hold the plant in the soil; take in water and minerals |
| Stem | holds up the leaves and flower; carries water and minerals up, and food from the leaves |
| Leaves | catch light and use it to make food |
| Flower | makes seeds |
A tree has the same four main parts as a bean plant. Its trunk is a thick, woody stem. Its flowers may be small and hard to see, but they still make seeds.
Key ideas
- All four main parts of a plant work together.
- A tree has the same four main parts as a bean plant.
- A tree trunk is a thick, woody stem.
- If the roots are damaged, the plant may not take in enough water.
Method. Think about the jobs of the roots.
- Think about the first job. Roots hold the plant in the soil.holding in soil
- Think about the second job. Roots take in water and minerals from the soil.water and minerals
- Write the two jobs. Without roots, the plant cannot hold itself in the soil, or take in water and minerals.holding and taking in
- Write the answer. holding the plant in the soil, and taking in water and minerals
Check. Both jobs belong to the roots. ✓
Method. Think about which part uses light to make food.
- Read roots. Roots take in water and minerals, but they do not make food.roots: no
- Read flower. The flower makes seeds, not food for the whole plant.flower: seeds
- Read leaves. Leaves use light to make food for the whole plant.leaves: food
- Write the answer. leaves
Check. The leaves are the food-makers of the plant. ✓
Method. Think about what both parts do.
- Look at the bean stem. The bean stem holds up the leaves and flower, and carries water and food.holds up and carries
- Look at the trunk. A tree trunk holds up the branches and leaves, and carries water and food too.holds up and carries
- Compare them. Both are stems, so they do the same jobs.both are stems
- Write the answer. Both are stems, so they hold up the leaves and flowers, and carry water and food.
Check. A trunk is a thick, woody stem. ✓
Watch out
Watch out: a tree is a flowering plant too, even though its flowers may be small and hard to see. A tree has the same four main parts.
Try it at home or school (with a grown-up). Choose a tree in a park or garden with a grown-up. Look at its trunk, its leaves and any flowers. Do not dig or touch the roots. Draw one labelled picture, with the words roots, trunk, leaves and flower. Wash your hands afterwards if you touched anything.
Exam tip
Grown-up tip. Ask: “What job does each part do? What would happen if the roots were cut?” Let your child explain the tree picture to you, part by part.
Exercise 2F The parts working together
Method. Think about the thick, woody stem of a tree.
- Think about the tree. The thick, woody stem of a tree is its trunk.trunk
- Compare with the bean. The bean plant stem is the same kind of part.same kind of part
- Write the answer. trunk
Check. The trunk and the stem are both stems. ✓
Method. Think about the part that is in the soil.
- Think about the soil. The part in the soil holds the plant in place.in the soil
- Name the part. The roots hold the plant in the soil.roots
- Write the answer. roots
Check. The roots hold the plant in place. ✓
Method. Think about the part of the plant that makes seeds.
- Think about the seeds. Seeds come from flowers.from flowers
- Name the part. The flower makes seeds.flower
- Write the answer. flower
Check. The flower makes seeds. ✓
Method. Think about the part that joins the roots and the leaves.
- Think about the path. Water goes from the roots, up through the middle of the plant.up from roots
- Name the part. The stem carries the water up.stem
- Write the answer. stem
Check. The stem carries water up. ✓
| Part | Main job |
|---|---|
| Roots | hold the plant in the soil; take in water and minerals |
| Stem | holds up the leaves and flower; carries water and minerals up, and food from the leaves |
| Leaves | catch light and use it to make food |
| Flower | makes seeds |
Method. Find the stem row in the table.
- Find the row. The stem row is the second row.second row
- Read the first job. The first job in that row is holds up the leaves and flower.holds up the leaves and flower
- Write the answer. holds up the leaves and flower
Check. The table lists the stem’s jobs in order. ✓
Method. Think about where the water starts and how it reaches the leaves.
- Think about the start. The water is taken in by the roots from the soil.roots
- Think about the path. The water then travels up the stem to the leaves.stem
- Write the answer. roots and stem
Check. The roots take in the water and the stem carries it up. ✓
Method. Add the leaves on the two stems.
- Read the numbers. One stem has 4 leaves and the other has 5 leaves.4 and 5
- Add them together. The total is the number of leaves on both stems.4 + 5 = 9
- Write the answer. 9 leaves
Check. 5 + 4 = 9, so the answer is right. ✓
Method. Choose one part to compare, and one thing you can measure or count.
- Choose a part to compare. The stem of the bean plant and the trunk of the tree are both stems.stem and trunk
- Choose a measurement. You could measure the height in cm, or count the number of leaves.height or leaves
- Write the answer. Accept any plan that names a part, such as the stem or trunk, and a measurement, such as its height in cm or the number of leaves.
Check. A fair comparison uses one part and one measurement. ✓
Method. Compare what each one does.
- Think about the bean stem. The bean stem holds up the leaves and carries water and food.holds and carries
- Think about the trunk. The trunk holds up the branches and leaves, and carries water and food too.same jobs
- Write the answer. yes
Check. Both are stems that do the same jobs. ✓
Method. Think about which part is in the soil.
- Think about the leaves. Leaves grow above the soil and make food.leaves make food
- Name the right part. The roots hold the plant in the soil.roots
- Write the answer. No. Accept any answer that says the roots hold the plant in the soil.
Check. The roots are the part that holds the plant in the soil. ✓
Method. Think about where the water starts.
- Start in the soil. The water starts in the soil, and the roots take it in first.roots first
- Follow the path. Then the water goes up the stem, and reaches the leaves last.stem then leaves
- Write the answer. roots, stem, leaves
Check. Roots, then stem, then leaves. ✓