Dispersal of Seed is the important factor to maintain offspring, Fertilized ovule forms seed when the fertilization takes place. Fruits protect seeds. They are different in shape and size.
Like humans, plants also need nutrients to survive and grow.
Plants absorb most of the nutrients from the soil.
If many seeds fall just under the plant and around it, the land will not be enough to supply nutrients to all the plants.
In this condition, plants will not grow well.
Thus, it is necessary to scatter the seeds far from the plants where they form.
The process is called the dispersal of seed.
There are the following ways of dispersal of seeds.
A. By Air (wind dispersal)
In some plants there are wingy, feathery and hairy structures attached with seeds.
The structures help the seeds to fly wind.
The wind transports the seed for a significant distance.
When the seeds get a suitable environment there, they grow in the form of new plants.
Cotton, simal, etc. have a hairy structure in their seeds, which help them to fly.
Maple seeds have a wing-like structure that carries the seed away from the plant.
Dandelions have a parachute-like structure that helps seeds fly in the for the dispersal of seeds.
B. By Water (water dispersal)
some plants grow at shores and banks of rivers.
Their seeds fall in the shores and the river carries the seed very far from the mother plant. when they reach suitable conditions they grow in the form of new plants.
The seeds of coconut, beetle nut, lotus, water Lillies, etc. are dispersed by this method.
C. By explosive action of fruits
Fruits of some plants when ripe, burst forcibly.
It makes the seeds to scatter to a longer distance.
Usually, pods disperse their seeds by this method.
blossom, pea, bean, etc. disperse their seed by this method.
D. By animals
We modify seeds of plants are in different ways.
some of them like burrs have spiky hooks that stick in the hairs of those animals which come in contact with them.
When the animals rub their bodies at other places, the seeds fall there.
Animals eat fruits of plants which helps the dispersion of seed.
When birds carry fruit from one place to another, they leave the seed at that place by eating the fruit.
human beings and other animals also disperse seeds by eating fruit.
Sometimes when the seeds are eaten with fruit, the seeds come out with faeces.
It is also a way of dispersal of seed.
Human beings also transport seeds of quality fruits from one place to another to grow them.
In this way, seeds are dispersed from one place to another.
Germination of seed
when seeds get suitable conditions their embryos activate and grow.
Suitable temperature, water, and air make the embryo active to grow.
The process by which the embryo is activated and grows in the form of seedlings is called the germination of seed.
During germination, at first, radicle comes out from the seed and then only the plumule comes out.
The radicle grows into its root and plumular grows into its shoot.