Chapter 7 of 8

All 8 chapters
  1. 1Plant parts and their jobs, readunderstood
  2. 2From seed to seedling, readunderstood
  3. 3A fair test with plants, readunderstood
  4. 4Light, water and plant health, readunderstood
  5. 5Leaves make food, readunderstood
  6. 6Flowers and pollination, readunderstood
  7. 7How seeds travel, readunderstood
  8. 8The life cycle of a plant, readunderstood

S2.1.7 Chapter 7

How seeds travel

How do seeds get away from the plant?

Your guess

Pick one before you read on. It is fine to be wrong.

Your guess

  • You picked A. Read on. At the end, the chapter comes back to your guess.

  • You picked B. Read on. At the end, the chapter comes back to your guess.

  • You picked C. Read on. At the end, the chapter comes back to your guess.

By the end you can

  • Sort seeds by how they travel: wind, water, animals or bursting pods
  • Explain why seeds that travel far have a better chance to grow

A plant cannot walk. But its seeds can travel. Some go far from the plant.

Some seeds travel on the wind. They are very light. They have fluff or thin wings.

Some seeds travel on water. A coconut can float on the sea for weeks. Then it lands on a new shore.

Two small pictures. On the left, a seed with a thin wing and three arrows for the wind, labelled wind. On the right, a coconut floating on waves with an arrow above it, labelled water. Labels: wind, water.windwater
A wing catches the wind. A coconut floats on water.

Some seeds travel on animals. They have hooks. The hooks stick to fur and to your socks.

Other seeds are inside a fruit. A fruit is the part of a plant that holds the seeds. An animal eats the fruit whole.

Later the animal leaves droppings far away. Droppings are waste that comes out of an animal. The seeds are in them. Some animals bury nuts and forget them. The nuts grow.

Two small pictures. On the left, a burr with hooks caught in the hair on the back of an animal, labelled animal. On the right, a fruit with seeds inside, an arrow to a bird, and an arrow down to droppings on the ground with the seeds inside, labelled eaten. Labels: animal, eaten.animaleaten
Hooks stick to fur. An eaten fruit leaves its seeds in droppings.

Some seeds travel when a pod bursts. A pod is a case that holds seeds. Some bean pods dry in the sun. They twist open and fling the seeds.

A dry pod split open into two halves. Three arrows lead away from it, and a seed lies at the end of each arrow. Labels: pod.pod
A dry pod twists open and flings its seeds.

See it three ways

As a picture

Four rows. Each row has a way to travel, an arrow, and what the seed has. Wind: fluff or wings. Water: it floats. Animals: hooks or eaten. Pods: twist and fling. Labels: wind, fluff or wings, water, it floats, animals, hooks or eaten, pods, twist and fling.windfluff or wingswaterit floatsanimalshooks or eatenpodstwist and fling

In words

Wind carries light seeds. Some seeds float on water. Animals carry hooked seeds or eat the fruit. Pods fling their seeds.

Why do seeds travel? Think about a seed that falls right under its parent plant.

The parent already uses the light, water and space. The seeds must share. Few of them grow well.

Draw it first

Draw where seeds land

  1. A parent plant stands in the ground. Seeds lie close round its base, labelled crowded. Two arrows lead away from the plant, left and right. More seeds lie far away on both sides, labelled far apart. The plant is labelled parent plant.parent plant

    1 Draw a plant in the ground. Write parent plant.

  2. A parent plant stands in the ground. Seeds lie close round its base, labelled crowded. Two arrows lead away from the plant, left and right. More seeds lie far away on both sides, labelled far apart. The plant is labelled parent plant.parent plantcrowded

    2 Draw seeds close to the plant. Write crowded.

  3. A parent plant stands in the ground. Seeds lie close round its base, labelled crowded. Two arrows lead away from the plant, left and right. More seeds lie far away on both sides, labelled far apart. The plant is labelled parent plant.parent plantcrowdedfar apart

    3 Draw arrows away from the plant. Draw seeds far away. Write far apart.

A seed that travels far lands in open ground. It has room, light and water for itself. It has a better chance to grow.

Try it

Which seeds hitch a ride?

You need: an old sock, long grass or weeds, a cup.

Be safe: Wear shoes. Keep away from thorns and sharp plants. Never taste a seed. Wash your hands after.

  1. Pull the old sock over your shoe.
  2. Walk slowly through long grass and weeds.
  3. Sit down and take off the sock. Look at it closely.
  4. Pick off what is stuck. Put it in the cup.
  5. Look at one seed. Can you see a hook?

What you will see: Many small seeds are stuck to the sock. They have hooks or sticky tips. Animal fur would carry them the same way. The seeds drop off in a new place.

If you cannot try it, this is what happens.
A sock with small dots on it, labelled sock with seeds. An arrow points to one seed drawn big. It has short hooks all round it. It is labelled hooked seed.sock with seedshooked seed

A wrong idea many people have

Seeds grow best right under the parent plant.

Why it feels right: The parent grew well there. So the ground must be good for its seeds.

The test that breaks it: Fill two cups with the same soil. In one cup, sow 20 small seeds crowded together. Small seeds such as millet or mustard are good. In the other cup, sow 4 seeds spread apart. Give both cups the same light and water. After two weeks, look. The crowded seedlings are thin and weak.

What is true: Seeds under the parent share light, water and space. Few grow well. Seeds that travel reach open ground.

Key words

fruit
the part of a plant that holds the seeds.
pod
a case that holds seeds. It dries and twists open.
droppings
waste that comes out of an animal.

Back to your guess

The answer is A: Seeds travel in different ways.

Seeds travel by wind, water and animals. Some travel when pods burst. Some go far from the plant.

Check yourself

Try each one before you look. A wrong answer tells you where to go next.

  1. A seed has fluff like a tiny parachute. How does it travel?

    Tap your answer.

    1. Not this one. Seeds that ride on animals have hooks, or are eaten. Fluff catches the air. Try another.

    2. Not this one. Fluff is there so the wind can carry the seed far away. Try another.

    3. Not this one. Fluff catches the air. Seeds that travel on water float instead. Try another.

    4. Yes, that is right. The seed is light and the fluff catches the air. The wind carries it.

    See the answer

    On the wind

    The seed is light and the fluff catches the air. The wind carries it.

    • If you chose A: Seeds that ride on animals have hooks, or are eaten. Fluff catches the air.
    • If you chose B: Fluff is there so the wind can carry the seed far away.
    • If you chose C: Fluff catches the air. Seeds that travel on water float instead.

  2. Sort these by how they travel. A coconut. A burr with hooks. A bean pod. A seed with wings.

    See the answer

    Water: the coconut. Animals: the burr with hooks. Bursting pod: the bean pod. Wind: the seed with wings.

    A coconut floats. Hooks stick to fur. A dry bean pod twists open. Wings catch the wind.

  3. Why do seeds that travel far have a better chance to grow?

    Tap your answer.

    1. Not this one. Under the parent, seeds share light, water and space. Few grow well. Try another.

    2. Not this one. A seed does not get bigger on its trip. It lands in a place with more room. Try another.

    3. Yes, that is right. Seeds under the parent must share. Seeds that travel can have all they need.

    See the answer

    They reach open ground with room, light and water.

    Seeds under the parent must share. Seeds that travel can have all they need.

    • If you chose A: Under the parent, seeds share light, water and space. Few grow well.
    • If you chose B: A seed does not get bigger on its trip. It lands in a place with more room.

  4. A bird eats a whole berry. Later it drops the seed far away. How did the seed travel?

    Tap your answer.

    1. Not this one. The bird carried the seed inside it. The wind did not move it. Try another.

    2. Yes, that is right. The seed went inside the bird. It came out in the droppings, far from the plant.

    3. Not this one. A berry is not a dry pod. The bird carried the seed. Try another.

    See the answer

    Inside an animal

    The seed went inside the bird. It came out in the droppings, far from the plant.

    • If you chose A: The bird carried the seed inside it. The wind did not move it.
    • If you chose C: A berry is not a dry pod. The bird carried the seed.

  5. From an earlier chapter

    In science, which of these is a fruit?

    Tap your answer.

    1. Yes, that is right. A fruit is the part of a plant that holds the seeds. All three hold seeds.

    2. Not this one. A fruit is the part that holds the seeds. A bean pod and a tomato hold seeds too. Go to S2.1.6. Try another.

    3. Not this one. In cooking, a tomato is a vegetable. In science, it holds seeds, so it is a fruit. Go to S2.1.6. Try another.

    See the answer

    A bean pod, a tomato and a mango

    A fruit is the part of a plant that holds the seeds. All three hold seeds.

    • If you chose B: A fruit is the part that holds the seeds. A bean pod and a tomato hold seeds too. Go to S2.1.6.
    • If you chose C: In cooking, a tomato is a vegetable. In science, it holds seeds, so it is a fruit. Go to S2.1.6.

  6. Draw a plant with seeds under it and seeds far away. Say which seeds grow better.

    See the answer

    The seeds that are far away grow better. They have room, light and water.

    Seeds under the parent are crowded. They share light, water and space.

  7. Look at the three pictures. Which letter shows a seed that travels on water?

    Three small pictures, marked A, B and C. A shows a ball with hooks stuck in a hairy back. B shows a seed with a thin wing and three arrows pointing at it. C shows an oval floating on waves, with an arrow above it. Labels: A, B, C.ABC
    Tap your answer.

    1. Not this one. A shows a burr with hooks stuck in fur. That seed travels on an animal. Try another.

    2. Not this one. B shows a seed with a thin wing. The wing catches the wind. Try another.

    3. Yes, that is right. C shows a seed that floats on waves. Some seeds, such as a coconut, float and are carried by water.

    See the answer

    C

    C shows a seed that floats on waves. Some seeds, such as a coconut, float and are carried by water.

    • If you chose A: A shows a burr with hooks stuck in fur. That seed travels on an animal.
    • If you chose B: B shows a seed with a thin wing. The wing catches the wind.

  8. Some bean pods dry in the sun on the plant. How do they send their seeds out?

    Tap your answer.

    1. Not this one. Some seeds ride on animals. These dry pods open by themselves. Try another.

    2. Yes, that is right. As a pod dries it twists. It splits open and the seeds shoot out.

    3. Not this one. These pods do not need the wind. They twist open and fling their seeds. Try another.

    See the answer

    They twist open and fling the seeds.

    As a pod dries it twists. It splits open and the seeds shoot out.

    • If you chose A: Some seeds ride on animals. These dry pods open by themselves.
    • If you chose C: These pods do not need the wind. They twist open and fling their seeds.

Keep it

Copy this into your exercise book.

Seeds travel by wind, water, animals and bursting pods. Seeds under the parent share light, water and space. Few grow well. Seeds that travel reach open ground.

Draw: A plant with arrows to seeds far away. Write wind, water, animals, pods.

Reading with a child? A short page for the adult: what this chapter teaches and three questions to ask.

No internet tomorrow? Save the whole book as one file (922 KB). It opens on any phone.