Q. The second maturation division of the mammalian ovum occurs
A) In the Graafian follicle following the first maturation division
B) Shortly after ovulation before the ovum makes entry into the Fallopian tube
C) Until after the ovum has been penetrated by a sperm
D) Until the nucleus of the sperm has fused with that of the ovum
Explanation
[Solution from source] The secondary oocyte is released at ovulation arrested in meiosis II. It completes the second meiotic division only after a sperm enters it, producing the ovum and the second polar body. This happens before the sperm and egg nuclei fuse, so the nuclear-fusion option is wrong. Answer (3).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.