NEETZoologyHuman Reproduction
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): In human females, the second meiotic division of the oocyte is completed only if fertilization takes place. Reason (R): The entry of a sperm into the secondary oocyte induces the completion of the second meiotic division. In the light of the above statements, choose the correct answer from the opti
Options
- ABoth (A) and (R) are true and (R) is the correct explanation of (A)
- BBoth (A) and (R) are true but (R) is not the correct explanation of (A)
- C(A) is true but (R) is false
- D(A) is false but (R) is true
Correct answer
A. Both (A) and (R) are true and (R) is the correct explanation of (A)
Step-by-step solution
Assertion (A) is true because the secondary oocyte is released from the ovary in a state of meiotic arrest (at metaphase II). If no fertilization occurs, it degenerates without ever completing meiosis II. Reason (R) is true and correctly explains the Assertion. The entry of a sperm into the ovum (secondary oocyte) is the specific physiological trigger that breaks the meiotic arrest and induces the completion of the second meiotic division, resulting in the formation of a second polar body and a haploid ovum (ootid)