Question

100 eggs and 100 sperms can be produced from .......... and .......... meiotic divisions respectively.

• A. 100, 100
• B. 100, 25
• C. 25, 25
• D. 25, 100

Answer 1

Answer: (B)

100, 25

During spermatogenesis, spermatogonia undergo mitosis to produce a cell called 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 round of spermatogenesis forms four sperms from single primary spermatocyte, which means that 25 rounds of meiosis are needed to form 100 sperms.

During oogenesis, primary oocyte undergoes first meiotic division to produce one secondary oocyte (egg cell) and one polar body (nonfunctional cell). Thus, one meiotic cycle in a primary oocyte produces one egg cell, which means that 100 egg cells are produced by 100 meiotic cycles.

Thus, the correct answer is option B.