Question: 138. Consider the following:
A. The reductive division for the human female gametogenesis starts earlier than that of the male gametogenesis.
B. The gap between the first meiotic division and the second meiotic division is much shorter for males compared to females.
C. The first polar body is associated with the formation of the primary oocyte.
D. Luteinizing Hormone (LH) surge leads to disintegration of the endometrium and onset of menstrual bleeding.
Choose the correct answer from the options given below:
(1) A and B are true
(2) A and C are true
(3) B and D are true
(4) B and C are true
Answer: Option (1)
Explanation:
In females, meiosis begins during fetal development when oogonia initiate meiosis I to form primary oocytes. This occurs much earlier than in males, where meiosis begins only at puberty. Thus, statement A is true.
In males, meiosis I and meiosis II occur in rapid succession during spermatogenesis. In females, however, there is a long gap: meiosis I completes at puberty during ovulation, and meiosis II completes only after fertilisation. Therefore, statement B is true.
The first polar body is formed after completion of meiosis I, not during formation of the primary oocyte. Hence, statement C is false.
The LH surge triggers ovulation, not menstrual bleeding. Menstruation occurs due to a drop in progesterone when the corpus luteum degenerates. Therefore, statement D is false.