Ncert Exercises & Solutions

The spermatogonia undergo division to produce sperm by the process of spermatogenesis. Choose the correct one with reference to above.

1.	Spermatogonia have 46 chromosomes and always undergo meiotic cell division.
2.	Primary spermatocytes divide by mitotic cell division.
3.	Secondary spermatocytes have 23 chromosomes and always undergo second meiotic cell division.
4.	Spermatozoa are transformed into spermatids.

NEETprep Answer:

In testis, the immature male germ cells (spermatogonia) produce sperms by spermatogenesis. The sperrnatogonia present on the inside wall of seminiferous tubules muitiply by mitotic division and increase in numbers.

Each spermatogonia is diploid and contains 46 chromosomes. 2n Some of the spermatogonia Called primary spermatocytes periodically undergo meiosis. A primary spermatocyte completes ihe first meiotic civision (reduction division) leading to formation of two equal, haploid celle callod secondary spermatocytes, which have orily 23 chrornosomes each (n).

The secondary spermatocytes undergo the second phage of meiotic division to produce four equal, haploicl spermatids. The spermatids are transformed into spermatozoa (sperms) by the process called spermiogenesis.

Option	Statement	NCERT-based ans
1. Spermatogonia have 46 chromosomes and always undergo meiotic cell division.	Spermatogonia are diploid (46), but they divide mitotically, not meiotically.	Incorrect
2. Primary spermatocytes divide by mitotic cell division.	Primary spermatocytes divide by meiosis I, not mitosis.	Incorrect
3. Secondary spermatocytes have 23 chromosomes and always undergo second meiotic cell division.	True — they are haploid (23) and undergo meiosis II to form spermatids.	Correct
4. Spermatozoa are transformed into spermatids.	Opposite — spermatids transform into spermatozoa (spermiogenesis).	Incorrect

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