Question

Capacitation means
A. Spermiogenesis
B. Formation of ovum covering
C. Development of the egg to meet the sperm
D. Activation of sperm to fertilize the egg

Answer 1

Hint: Capacitation is the process in the maturation of mammalian spermatozoa and is required to help them be capable of fertilising oocytes. Capacitation can cause the signals, which starts the removal of spermatozoa.

Complete answer:
- Spermiogenesis: It is the process in which the spermatids undergo a series of complex changes and results in the development of mature spermatozoa. Several changes take place during spermiogenesis such as centrioles migrate to the opposite end of the spermatids and form the proximal and distal centriole in the neck region of the sperm.
- Formation of the ovum covering: The ovum at the time of ovulation is covered by corona radiata which is composed of follicular cells. The inner part of the corona radiata consists of zona pellucida which is a transparent layer and it is composed of glycoprotein.
- Development of the egg to meet the ovum: The egg cells are produced by the ovaries and are known as the ova or oocytes. The oocytes are then transferred to the fallopian tube where the fertilization by a sperm may take place.
- Activation of sperm to fertilize the egg: Capacitation is the process to activate the sperm which helps in the fertilization of the egg. The fertilized egg must first complete the second meiotic division to produce the haploid maternal pronucleus.
Hence, the correct answer is, ‘D. Activation of sperm to fertilize the egg’.

Note: The term capacitation was first described by Colin Russell Austin and Min Chueh Chang in 1951. This process first experimented on rats and rabbits respectively.