Question

How many secondary spermatocytes will form 400 spermatozoa?
A) 100
B) 400
C) 40
D) 200

Answer 1

Hint:Spermatozoa (sperm) are the male sex cells that carry a man's genetic material.Secondary spermatocytes are haploid (N) cells that contain half the number of chromosomes.

Complete answer:
Spermatogenesis is the process by which haploid spermatozoa develop from germ cells in the seminiferous tubules of the testis. This process starts with the mitotic division of the stem cells located close to the basement membrane of the tubules. These cells are called spermatogonial stem cells. The regulation of spermatogenesis involves both endocrine and paracrine mechanisms. The endocrine stimulation of spermatogenesis involves both follicle stimulating hormone (FSH) and luteinizing hormone, the latter acting through the intermediary testosterone, produced by the Leydig cells in the testis. Since the germ cells do not possess receptors for FSH and testosterone, the hormonal signals are transduced through the sertoli cells and peritubular cells by the production of signals that have yet to be defined. The final complex metamorphosis which converts a round cell into the complex structures of the spermatozoa is well defined at a structural level, but the control systems regulating this process still remain to be elucidated.

Each secondary spermatocyte divides into two spermatids. Thus, 100 primary spermatocytes will undergo meiosis to produce 200 secondary spermatocytes which will give rise to 400 spermatids. The 400 spermatids will ultimately form 400 spermatozoa.

Therefore the correct answer is option (D).

Note:Spermatocytes are found in the testis, in a structure known as the seminiferous tubules. There are two types of spermatocytes, primary and secondary spermatocytes.