What is the result of the first meiotic division of a primary spermatocyte?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Two haploid cells called secondary spermatocytes
Spermatogenesis takes place in the seminiferous tubules of the testis. Diploid spermatogonia multiply by mitosis, and some of them become primary spermatocytes, which undergo meiosis. Meiosis has two divisions: the first is the reduction division (the chromosome number is halved), and the second gives four spermatids.
Option (1) Two diploid cells called spermatogonia — Incorrect. Spermatogonia are the cells before the primary spermatocyte. They are formed by mitosis, not by the meiotic division of a spermatocyte.
Option (2) Two haploid cells called secondary spermatocytes — Correct. The first meiotic (reduction) division of a primary spermatocyte gives two equal, haploid cells called secondary spermatocytes, each with 23 chromosomes.
Option (3) Four haploid cells called spermatids — Incorrect. Four haploid spermatids are formed only after the second meiotic division, when each of the two secondary spermatocytes divides.
Option (4) Two diploid cells called spermatids — Incorrect. Spermatids are haploid, not diploid, and they are formed after the second meiotic division, not the first.
NCERT Extract:
Gametogenesis – “… Each spermatogonium is diploid and contains 46 chromosomes. Some of the spermatogonia called primary spermatocytes periodically undergo meiosis. A primary spermatocyte completes the first meiotic division (reduction division) leading to formation of two equal, haploid cells called secondary spermatocytes, which have only 23 chromosomes each. The secondary spermatocytes undergo the second meiotic division to produce four equal, haploid spermatids (Figure 2.5).”