What happens during fertilisation in humans after many sperms reach close to the ovum ?

Options

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

Answer

C

Explanation

During fertilization a sperm comes in contact with the zona pellucida layer of the ovum and induce changes in the membrane thus block the entry of additional sperm. The secretion of the Acrosome help the sperm enter into the cytoplasm by release of hydrolytic enzyme called sperm lysin. It is known as acrosomal reaction. Acrosome reaction results in dissolving of corona cells and degeneration of zona pellucida which help in sperm penetration.