Seed - Notes For Neet

Seed 

Seeds are developed from ovules of a ovary after the fertilization of male gamete and female gamete.

Female gamete (egg cell) is already present in ovules and male gamete comes from anther in the form of pollen grain.

A seed contain mainly three parts -

1. Seed coat

2. Cotyledon

3. Embryo


1. Seed coat -

it is outermost part of a seed which is hardest in composition seed coat contain two layers mostly that is called tagmen and testa.

Seed coat is not a permeable for water so it contains dormanag of seed.

At the end of seed coat a minut pore is present that is called microphyle.

When a seed germinates then it absorbs water through the micropyler pore.

2. Cotyledon

It is just internal part of a seed then seed coat.

Cotyledons are specified for food storage.

The provides a food to the embryo at the time of seed germination.

On the basis of member of a cotyledon seed is divided into two parts.

A. Monocot seed

B. Dicot seed

3. Embryo


A seed content to embryos for plant development

1. Plumule

2. Radicle

Plumule is generated in the form of shoot system while radical is it develops in the form of root system (primary root)

Difference between monocot and dicot seed - 

A. Monocoat Seed -

Single cotyledon is present.

Les developed cotoledon  is present.

Endosperm is developed.

Endosperm give nutrition for seed germination.

adventures root se are formed because radical get reduced at the time of shoot formation from plumule.

Plumule is covered by coleaptile and radicle is covered by coteorrhiza.

Example - wheat, rice, maize, Bajra etc

B. Dicot Seed -

Double cotyledon is present.

Well developed cotyledon are present.

Endosperm not a developed a completely used at the time of seed formation.

Cotyledon give nutrition for seed germination.

Tap root is formed.

No covering on plumule or radical.

Example - pulses, pea, groundnut etc.