Question

Given below is the diagram of a human ovum surrounded by a few sperms. Observe the diagram and answer the following questions :

(a) Compare the fate of sperms shown in the diagram.

(b) What is the role of zona pellucida in this process ?

(c) Analyze the changes occurring in the ovum during the process.

(d) How is the entry of sperm into the ovum facilitated ?

(e) Specify the region of female reproductive system where the event represented in the diagram takes place.

Answer 1

(a) A is able to penetrate/fertilize the ovum, whereas B and C are unable to penetrate/ fertilize/B and C will degenerate. 

(b) Zona pellucida ensures the entry of only one sperm into the ovum.

(c) induces completion of meiotic division of the secondary oocyte, formation of second polar body and a haploid ovum.

(d) Enzymes of acrosome help

(e) Ampullary - isthmic junction of the fallopian tube.