Question

Preparation of sperm before it penetrates the ovum is called:

• A. spermiation
• B. cortical reaction
• C. spermiogenesis
• D. capacitation

Answer 1

The correct option is D capacitation

Capacitation refers to the physiological changes in sperm which enable it to penetrate and fertilise ovum. These events take place during passage of sperm within the female reproductive system.

During capacitation, the medium inside the uterus wears off the plasma membrane of the sperm head. This exposes the acrosome of sperm making it highly penetrable. It also increases the motility of sperm.

Spermiogenesis is a process of transforming spermatids into spermatozoa. Later, these spermatozoa get embedded in the Sertoli cells to draw nourishment and then they are released in the lumen of seminiferous tubules.

The process in which sperms are released from Sertoli cells into the lumen of seminiferous tubules is called spermiation.

The cortical reaction causes cortical granules to be released from the cytoplasm of oocyte into the perivitelline space immediately after fertilization and thus it prevents the polyspermy.