Question

Capacitation refers to changes in the

• A. Ovum after fertilization.
• B. Sperm after fertilization.
• C. Sperm before fertilization.
• D. Ovum before fertilization.

Answer 1

Answer: (C)

Sperm before fertilization.

Capacitation is the penultimate step in the maturation of mammalian spermatozoa and is required to render them competent to fertilize an oocyte. This step is a biochemical event; the sperm move normally and look mature prior to capacitation. In vivo, this step typically occurs after ejaculation, in the female reproductive tract. In vitro, capacitation can occur by incubating sperms that have either undergone ejaculation or have been extracted from the epididymis in a defined medium for several hours.
The uterus aids in the steps of capacitation by secreting sterol-binding albumin, lipoproteins, proteolytic and glycosidasic enzymes such as heparin.