Q. Identify the structures labelled as A and B.
Question
A B
(A) Spermatogonia Spermatid
(B) Oocyte Spermatozoa
(C) Spermatid Spermatozoa
(D) Spermatogonia Spermatozoa

 2045  132 NTA AbhyasNTA Abhyas 2020Human Reproduction Report Error

Solution:

The spermatogonia (sing. spermatogonium) are present on the inside wall of seminiferous tubules, and they increase in numbers by mitotic division. Each spermatogonium is diploid and contains 46 chromosomes.
Some spermatogonia are called primary spermatocytes, which undergo meiotic division. They form second spermatocytes, which divide meiotically and give rise to haploid spermatids. They transform into spermatozoa (sperms) by the process called spermiogenesis.