Page 8 - Science - 5

plant inside. The baby plant is present

between the cotyledons. It develops a new
root system and a shoot system and grows

into a new plant.
Seeds like rajma, bean and pea have two

Dicotyledonous Seeds cotyledons. They are called dicotyledonous

dicot seeds . Some seeds like rice, maize and wheat have a single cotyledon.

They are called monocotyledonous (monocot) seeds .

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Seeds should be sown with proper gaps so that, they could get sufficient air,
water, sunlight, nutrients and space to grow.

GERMINATION OF SEEDS

The development of a new plant from a seed is
called germination . A seed needs the right

amount of water, air and warmth to germinate.

Stages of Seed Germination
The seed first absorbs water through its hole.
Stages of seed Germination
This softens the seed coat, so it ruptures.

A small root emerges from the seed. It is
Activity - Soak some grams in
called the radicle . It grows downwards. Then
water for few hours. They will

absorb water and will become a small shoot emerges from the seed. It is
large. Now put them in a wet called the plumule . It grows upwards. The
cotton for one day. See what seed with a small root and a small shoot is

happens? A tiny plant starts to called a seedling . The growing seedling uses
grow from each seed. the food stored in the cotyledons for growth.

After a few days, green leaves start appearing on the shoot. These leaves
make food by the process of photosynthesis. The cotyledons dry up and fall off
as all the food in them is used up. The seedling then develops into a new plant.

SEED DISPERSAL

The process of scattering of seeds to different places is called seed dispersal .
Seeds need to be dispersed because if they are not dispersed, many

germinating seedlings will grow very close to the parent plant. This will result in

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