Question

Arrange the following with regard to their occurrence in spermatogenesis.
(a) Spermatogonia (b) Secondary spermatocyte (c) Spermatogonial stem cells (d) Primary spermatocyte (e) Spermatid
(A) c-d-b-a-e
(B) c-a-d-b-e
(C) a-b-c-d-e
(D) c-d-a-b-e

Answer 1

Hint: Humans are sexually reproducing and viviparous organisms. When they reproduce they include formation of gametes (gametogenesis), i.e., sperms in males and ovum in females, respectively and then occurs the transfer of sperms into the female genital tract (insemination) and after that there occurs fusion of male and female gametes (fertilisation) leading to formation of zygote.

Complete answer:
The formation and production of male gamete is known as spermatogenesis.
Spermatogenesis:-
In testis, the immature male germ cells, spermatogonia produce sperms by a process spermatogenesis that begins at puberty. Spermatogenesis occurs in four stages: (i ) Spermatocytogenesis, (ii) Meiosis-l (iii) Meiosis-II and (iv) Spermiogenesis.

(i) Spermatocytogenesis : In spermatocytogenesis, the spermatogonia remains attached on the inside wall of the seminiferous tubules multiply by mitotic division and multiply in numbers. Some spermatogonia changes in their structure as they grow, increase in size by assimilating nourishing materials and are called primary spermatocytes which periodically undergo meiosis and others remain as spermatogonia.

(ii) Meiosis-1: A primary spermatocyte is diploid, (2n) with 44 + XY (total 46) chromosomes. It undergoes the the first meiotic division (reduction division) and after completion it is leading to the formation of two equal, haploid cells called secondary spermatocytes,

(iii) Meiosis-ll: The secondary spermatocytes undergo the second meiotic division to produce four equal, haploid spermatids.

(iv) Spermiogenesis : Transformation of spermatid into sperm is termed spermiogenesis.

Hence, the correct answer is option (B)

Note: The primary sex organs - the testis in the males and the ovaries in the females, produce gametes i.e. sperms and ovum respectively, by the process called gametogenesis. The ovary is the primary female sex organ. It produces ova and secretes the female sex hormones, oestrogens and progesterone which are responsible for the development of secondary female sex characters.