Question

Receptors for sperm binding in mammals are present on

• A. Zona pellucida
• B. Vitelline membrane
• C. Perivitelline space
• D. Corona radiata

Answer 1

The correct option is A

Zona pellucida

The correct option is A.

Explanation of correct option:

1. The zona pellucida refers to a thick extracellular glycoprotein membrane surrounding the mammalian oocyte membrane.
2. It has ZP3 receptors that plays a key role in sperm-egg binding.

Explanation of incorrect options:

Option B:

1. The vitelline membrane refers to a multilayered membrane that helps in protecting the egg yolk.

Option C:

1. The space in between the zona pellucida and the fertilized ovum is perivitelline space.
2. It helps in changing the size and composition of mammalian oocytes.

Option D:

1. The corona radiata is the innermost layer that protects the ovum.

Final answer: Receptors for sperm binding in mammals are present on zona pellucida.