Page 28 - 新思维科学学生用书5 样章

1.3 How seeds are spread

Some fruits drop and roll

Some fruits are heavy and round. When the fruits

are ripe, they drop from the tree and roll along the
ground. If the fruits have a tough outer shell, they

may roll quite far from the parent plant. Large
fruits that drop from high branches of the tree

roll further. Apple seeds are dispersed this way.

Fruits that have a softer skin may break open
when they hit the ground and scatter the seeds.

Animals that eat fallen fruits help to spread the

seeds further away from the parent plant.

Questions

1 A water lily seed has a spongy covering. How does this help a
water lily to disperse its seeds?

2 Why are bean pods usually picked before the weather gets
hot and dry?

3 Apple seeds are dispersed by the drop-and-roll

method. How else can the apple seeds be spread?
4 How are the seeds in this picture adapted for

wind dispersal?

Think like a scientist 1

Investigate how seeds are dispersed

You will need:

a variety of seeds, a hand lens, tweezers

• Collect at least five different kinds of seeds.

• Observe each seed carefully with a hand lens.

• Make a drawing of each seed. Label your drawings.
• Say how you think the seed is dispersed and how it is adapted to the type of dispersal.

• Sort your seeds into groups according to the way they are dispersed.

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