Question

In Spermatogenesis, reduction division of chromosome occurs during conversion of
A. Spermatogonia to primary spermatocytes
B. Primary spermatocytes to secondary spermatocytes
C. Secondary spermatocytes to spermatids
D. Spermatids to sperms

Answer 1

Hint: The sperm is the male gamete or the male reproductive cell. The sperms are motile cells and they bear a tail that is known as the flagellum. The sperms are also known as the spermatozoa. The sperms are produced in the testes through a process known as spermatogenesis.

Complete answer:
The testes is the male reproductive system and it produces the male gamete cell which is the sperms and male hormones. Spermatogenesis is the process of development of sperms or spermatozoa. The sperms develop from the germ cells in the seminiferous tubules of the testis.

The process of development of sperms starts with the germ cells that are present in the seminiferous tubules especially located towards the lining of the seminiferous tubules. These cells develop through mitotic division and are known as the spermatogonial germ cells or the spermatogonia. The mitotic division of the spermatogonial germ cells produce two types of cells which are the type A cells and the type B cells. The type A cells again work to replace the germ cells while the type B cells differentiate into the next types of cells, known as the primary spermatocytes.

After the formation of the primary spermatocytes, these cells undergo reduction division. The primary spermatocytes then divide through the process of meiosis and they divide into two secondary spermatocytes. Again each secondary spermatocyte divides meiotically into two equal haploid cells. These haploid cells are known as the spermatids. The meiotic division through which the primary spermatocyte forms the secondary spermatocyte is known as the first meiosis division and the division of secondary spermatocytes is called as the second meiosis. As the result of these two reduction divisions, the haploid spermatids are formed.

The spermatids then develop into the spermatozoa or sperm through the process of spermiogenesis. Finally, the spermatozoa matures and is known as the sperm. Hence, in the process of spermatogenesis, the primary spermatocytes produce two cells which are the secondary spermatocytes and again the secondary spermatocytes by the subdivision gives rise to spermatozoa and haploid cells.

Hence, The correct answer is option (B).

Note: The process of spermatogenesis is a step wise process to produce the male sex gamete which is the sperms. It occurs in the bottom portion of the seminiferous tubules. With the formation of germ cells, the process of spermatogenesis begins. The germ cells then divide and proliferate to produce the primary spermatocytes and the primary spermatocyte undergoes meiosis to produce the secondary spermatocytes.