INTRODUCTION -
- Fertilization is a complex process which involves fusion of male & female gametes.
- The male gamete in animals is called as sperm & the female gamete as ovum.
- Albert Tiler - Fertilization is a sequence of various events initiate through sperm.
- Austin - The fusion of male & female gametes to form zygote is called as fertilization.
- O. Hertwig - Fusion of male & female pronuclei is called as fertilization.
- Syngamy - Fusion of gametes in the fertilization is called as syngamy.
- Plasmagamy - Fusion of the cytoplasm of gametes.
- Karyogamy - Fusion of nucleoplasm.
- On the basis of shape & size gametes are two types -
1. Isogamy - In this male & female gametes are similar.
2. Anisogamy - The male & female gametes are different.
- Genetically contribution of male & female gametes is equal.
- According James Grey fertilization essential for -
1. Activation -
In this process cortex of egg activated & formed the fertilizine membrane over P.M.
Cytoplasm of ova initiate different metabolic activities, this activities essential for initiate cleavage.
2. Amphimixis -
In this process male & female pronuclei are fused and formed the diploid structure, i.e. zygote.
Genetic variation stimulate in the species.