Q. The second maturation division of the mammalian ovum occurs
A) Shortly after ovulation before the ovum makes entry into the fallopian tube
B) Until after the ovum has been penetrated by a sperm
C) Until the nucleus of the sperm has fused with that of the ovum
D) In the Graafian follicle following the first maturation division
Explanation
In mammalian ovum during maturation phase, meiosis occurs. Nucleus shift towards animal pole and undergoes meiosis-I. After fertilization (penetration of sperm), the second meiotic division is completes with unequal cytoplasmic cleavage. This forms a large cell the ootid with essentially whole of the cytoplasm and a very small cell, the second polar body.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.