Question

How many ova and sperms would be produced from 100 secondary oocytes and 100 secondary spermatocytes, during gametogenesis in humans?

• A. 100 ova, 100 sperms
• B. 100 ova, 200 sperms
• C. 50 ova, 100 sperms
• D. 200 ova, 200 sperms

Answer 1

Answer: (B)

100 ova, 200 sperms

The germ cells of seminiferous tubules present near the capsule serve as spermatogonia, which divide and produce more cells by mitosis. Some of these new cells serve as primary spermatocytes, that undergo meiosis; meiosis I produce two secondary spermatocytes (n) which is followed by meiosis II, that produces four spermatids.

Spermatids then differentiate into sperm. Thus, each secondary spermatocyte produces two sperms, which means that 100 secondary spermatocytes will produce 200 sperms.

During oogenesis, primary oocyte undergoes first meiotic division to produce one secondary oocyte (egg cell) and one polar body (non-functional cell). Thus, one secondary oocyte serves as one egg cell, which means that 100 egg cells are produced by 100 secondary oocytes. Thus, the correct answer is option B.