Science 5th grade
UNIT 2: The life cycle of flowering plants 2.2 How seeds are spread?
Science 5th grade
UNIT 2: The life cycle of flowering plants 2.2 How seeds are spread?
A fruit has two jobs:
• to protect the seeds inside
• to help spread the seeds.
Have you ever found seeds stuck in your socks? Plants need to scatter their seeds away from themselves. We call this seed dispersal.
Why seeds must be dispersed
Why do you think seeds must be dispersed?
What would happen if all the seeds grew next to their parent plant? What is happening to these seedlings?
Seedlings need room to grow. They also need light and water. Seedlings cannot grow to be healthy plants if they all have to share water and light in a small area. Plants disperse their seeds in different ways.
The pictures show how some plants disperse their seeds. Talk about how each seed is dispersed.
Some seeds are dispersed by animals
Animals can spread seeds. Birds, monkeys and even elephants eat colourful, juicy fruits. The seeds pass through the animal's body and are dispersed in the animal's droppings. This may be far away from where the animal ate the fruit.
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Some seeds have spines and hooks. These stick onto the fur of animals, or the clothes of people. Mice, ants and squirrels carry seeds away from the parent plant and bury them to eat later. If the animal does not eat the seeds, the seeds will germinate in the soil.
Activity 2.2: (Researching seed dispersal)
You will need: access to the internet and/or reference books about plants
Do some research to find out more about how seeds are dispersed by animals. You can find information in books or from the internet. Make a poster with drawings or pictures to show your findings.
Questions
1- Which seeds would grow better: those in a tomato left on the plant or those in a tomato eaten by a bird? Say why.
2- Do you think peach seeds can be dispersed by animals? Say why or why not.
3- Make a drawing of a seed you think would be dispersed in an animal's fur.