Answer:
Zona pellucida, Sperm receptors are the correct answer to this question.
Explanation:
Zona pellucida:-
- Zona pellucida is an immunoglobulin substance that protects mammalian oocyte cell membranes at all times. It is a very important part of oocyte.
- The zona pellucida always occurs unilaminar in primary oocytes.
Sperm receptors:-
- When fertilization in mammals, sperm must first attach to the egg's thick epithelial layer, the area pellucida, in a species-specific manner.
- ZP3 is the receptor that binds sperm at the start of fertilization in the zona pellucida.