What are the chemical events of fertilisation in mammalian egg
Answers
When mammalian egg and sperm come into contact in the female oviduct, a series of steps is set in motion that can lead to fertilization and ultimately to development of new individual. Hence, fertilization is the process of union of an ovum with the sperm. Site of fertilization is fallopian tube (ampulla)
Mammalian eggs have very less amount of yolk, that's why eggs are oligolecithal & isolecithal or microlecithal & homolecithal. 0.1 mm is the usually size of mammalian eggs.
These type of eggs has 2 egg-membranes:
(1) Zona pelucida: It is a transparent membrane like covering & is a primary membrane secreted by the ovum or oocyte.
(2) Corona radiata: It is a layer of follicular cells & these cells are attached to the surface of egg with hyaluronic acid. This is constituted as the secondary membrane, which is secreted by the ovary. These eggs do not have tertiary membrane.