Year 1 Science: Stems and trunks: holding up and carrying water
Part of the Year 1 Science parts of a plant chapter. Chapter overview · whole chapter on one page · Download worksheet (PDF) · Answers (PDF)
Stems and trunks: holding up and carrying water
The stem holds up the leaves and the flower. It has tiny tubes inside it. Water goes up these tubes from the roots to the leaves and the flower.
A tree has a very thick stem called the trunk. The trunk holds up the branches and the leaves.
Key ideas
- The stem holds up the leaves and the flower.
- Water goes up the stem from the roots.
- A tree’s thick stem is called the trunk.
- Some stems are thin and soft, like a flower stalk.
Key words. To count is to say one number for each thing, in order: 1, 2, 3, and so on.
Method. Touch each one once and say its number. The last number is how many.
- Count the leaves. Touch each one once, so you do not miss one or count one twice.1, 2, 3, 4
- Look at the last number you said. The last number tells us how many there are.The last number is 4.
- Write the answer. There are 4 leaves.
Check. Count again from the other side. You still get 4. ✓
Watch out. Move each one to one side as you count it. Do not count the same one twice.
Method. Think about the part that joins the roots to the leaves.
- Think about the path of the water. Water starts in the roots and goes up.Roots -> up -> leaves
- Find the part on the way. The stem is the part between the roots and the leaves.The stem is in the middle
- Write the answer. The stem
Check. Look at the stem in the picture. It goes from the pot to the leaves. ✓
Watch out. The roots take the water in, but the stem carries it up.
Method. Think about the big stem of a tree.
- Think about a tree. A tree has a big, thick stem going up from the ground.A big stem = trunk
- Name it. The thick stem of a tree is called the trunk.Trunk
- Write the answer. The trunk
Check. The trunk holds up the branches. ✓
Watch out. Thin flower stalks are stems, but they are not trunks.
Watch out
Watch out: the stem is not the root. The stem grows up above the soil. The roots grow down into the soil.
Exam tip
Grown-up tip. Take a cut flower from a vase, with help, and look at its stem. Ask your child to count the leaves on the stem. On a walk, touch a tree trunk (wash hands after) and ask: Is it thin or thick?
Try it at home
With a grown-up, put a stick of celery with its leaves into a glass of water with a few drops of food colouring. Leave it for one day, then look at the leaves. Do not eat the celery afterwards. Wash your hands.
Exercise 3C Stems and trunks
Key words. To count is to say one number for each thing, in order: 1, 2, 3, and so on.
Method. Touch each one once and say its number. The last number is how many.
- Count the leaves. Touch each one once, so you do not miss one or count one twice.1, 2, 3
- Look at the last number you said. The last number tells us how many there are.The last number is 3.
- Write the answer. There are 3 leaves.
Check. Count again from the other side. You still get 3. ✓
Watch out. Move each one to one side as you count it. Do not count the same one twice.
Key words. To count is to say one number for each thing, in order: 1, 2, 3, and so on.
Method. Touch each one once and say its number. The last number is how many.
- Count the leaves. Touch each one once, so you do not miss one or count one twice.1, 2, 3, 4, 5
- Look at the last number you said. The last number tells us how many there are.The last number is 5.
- Write the answer. There are 5 leaves.
Check. Count again from the other side. You still get 5. ✓
Watch out. Move each one to one side as you count it. Do not count the same one twice.
Key words. To count is to say one number for each thing, in order: 1, 2, 3, and so on.
Method. Touch each one once and say its number. The last number is how many.
- Count the leaves. Touch each one once, so you do not miss one or count one twice.1, 2, 3, 4, 5, 6
- Look at the last number you said. The last number tells us how many there are.The last number is 6.
- Write the answer. There are 6 leaves.
Check. Count again from the other side. You still get 6. ✓
Watch out. Move each one to one side as you count it. Do not count the same one twice.
Method. Think about what the stem holds up.
- Read the sentence. The stem holds up the leaves and the flower.holds up the leaves
- Name the part. Leaves grow on the stem, and the stem holds them up.Leaves
- Write the answer. leaves
Check. Look at a plant on a windowsill. Its leaves point towards the light. ✓
Watch out. The stem does not hold up the roots.
Method. Think about the path that water takes.
- Think about each choice. Roots take in water. Petals are soft and bright, and do not carry water.Roots: take in. Petals: no.
- Choose the carrier. The stem carries water up to the leaves.Stem carries water up
- Write the answer. stem
Check. The stem has tiny tubes that carry water up. ✓
Watch out. Roots take in water. The stem carries it up.
Method. Think about different stems.
- Think about a flower stalk. A flower stalk is thin and soft.Thin flower stalk
- Decide. Not all stems are thick, so the sentence is false.False
- Write the answer. False
Check. A tree trunk is thick, but a flower stalk is thin. ✓
Watch out. Some stems are thin, and some are very thick.
Method. Think about the thick stem of a tree.
- Think about a tree. A tree has one big, thick stem.One big stem
- Name it. The thick stem of a tree is the trunk.Trunk
- Write the answer. trunk
Check. The trunk holds up the branches. ✓
Watch out. The trunk is a stem, but it is much thicker than a flower stalk.
Method. Add the leaves on both stems.
- Count the leaves on stem A. Stem A has 4 leaves.A = 4
- Count the leaves on stem B, and add them. Add the leaves on stem B to the leaves on stem A.4 + 2 = 6
- Write the answer. 6
Check. Count all the leaves again: 1, 2, 3, 4, 5, 6. ✓
Watch out. Add both stems. Do not only count one stem.
Method. Think about how water gets to a flower.
- Think about the stem. Water comes from the roots and goes up the stem to the flower.Stem carries water
- Think about the cut stem. Once the stem is cut off, no water can reach the flower.No water = droop
- Write the answer. It cannot get water, so it will droop.
Check. A flower in a vase has water in the vase, not from roots. ✓
Watch out. Water comes up through the stem from the roots.
Method. Think about the job of the stem.
- Think about the roots. The roots take in water from the soil.Roots take in water
- Think about the stem. The stem carries that water up to the leaves.Stem carries water up
- Write the answer. The stem carries water up from the roots to the leaves.
Check. Look at the stem in the picture. It joins the pot to the leaves. ✓
Watch out. Say both parts: roots take in water, and the stem carries it up.
Method. Think about how water moves up the stem.
- Think about the water. The stem carries water up to the leaves.Water goes up the stem
- Think about the colour. The coloured water goes up with the water, into the leaves.Coloured water reaches the leaves
- Write the answer. The leaves will change colour, because the coloured water goes up the stem.
Check. Look at the leaves tomorrow and see if they have changed. ✓
Watch out. Accept any answer that says the coloured water travels up the stem.