Page 12 - Active Science 5 Ebook and Activity

Observation : • The seed in beaker A does not germinate.

• The seed in beaker B shows germination.
• The seed in beaker C does not germinate.

Conclusion : This is because only seed B gets both water and air which are
necessary for germination. Seed A does not get air or oxygen and seed
C does not get water. However, a suitable temperature was there for
all the three seeds.

Let’s Recapitulate
State whether true (T) or false (F).

1. Seed absorbs water through hilum. ____
2. Cotyledons or seed leaves store food for a growth of a new plant. ____

3. The process by which seeds disperse into the new plant is known as germination. ____
4. Radical grows to form the root system. ____

Seed Dispersal

In case many seeds grow close to each other, they will compete for food, water and
sunlight. Therefore, it becomes necessary for the seeds to be dispersed away from the
parent plant. The process of spreading seeds to different places is called seed dispersal.

Seeds are dispersed in a number of ways. They may be carried by wind, water or animals.
In some plants, the fruits explode, releasing a number of seeds in the air.

Dispersal by Wind

The seeds of some plants are very light Dandelion Seeds
in weight. They also have stiff wings that
allow them to fly long distances. Such seeds

are easily carried by wind. Examples of
plants whose seeds are dispersed by wind
are maple, cotton, hiptage and dandelion.
Cotton Seeds
Dispersal of Seeds by Water
Seeds
Plants which grow in rivers, oceans and
ponds or near water bodies use water for
dispersal of seeds. Some fruits are so light
that they can float on water and are carried Maple Seeds

Lotus Seeds

12 Active Science-5