G. Seed
Seed: A reproductive unit developed from afertilized, mature ovule
Composition
A seed consists of:
- Seed coat
- Embryo
(with or without endosperm)
Structure:
- Outermost covering
- Testa: Outer layer
- Tegmen: Inner layer
Hilum
- Scar on seed coat
- Point through which seed attaches to fruit
Embryo and its Parts
Embryonal Axis:
- Consists of radicle and plumule
Epicotyl:
- Part of embryonal axis between cotyledon and plumule
Hypocotyl:
- Part between cotyledons and radicle
Cotyledons:
- One or two present in embryo
Endosperm
- Definition: Nutritive tissue formed in seed
Types:
Endospermic Seed
- Food is
partially used up
- Example: Castor
- Food is
completely used up
- Example: Pea
