Question

What happens during fertilization when many sperms reach close to ovum?

• A. Cells of corona radiata trap all the sperms except one
• B. Only two sperms nearest to ovum penetrate zona pallucida
• C. Secretion of acrosome helps one sperm enter cytoplasm of ovum through zona pellucida
• D. All sperms except the one nearest to ovum lose their tails

Answer 1

Answer: (C)

Secretion of acrosome helps one sperm enter cytoplasm of ovum through zona pellucida

The process of the meeting of a sperm with an ovum is called fertilisation. During fertilization, a sperm comes in contact with the zona pellucida layer of the ovum and acrosome releases some factors which induce changes in the membrane that blocks the entry of additional sperms. Thus, it ensures that only one sperm can fertilise an ovum.

So, the correct option is 'Secretion of acrosome helps one sperm enter cytoplasm of ovum through zona pellucida'.