(E), (A), (D), (B), (C)
(E) (A), (D), (C), (B)
(E), (A), (C), (D), (B)
(D), (E), (A), (B), (C)
Spermatogenesis involves the creation of sperm in males, occurring within the seminiferous tubules located in the testes. During this process,
(a) Spermatogonia, located on the inner wall of the seminiferous tubules, undergo mitotic division, resulting in an increase in their numbers.
(b) Every spermatogonium is diploid, housing a total of 46 chromosomes.
(c) Spermatogonia that periodically undergo meiosis are termed primary spermatocytes.
(d) When a primary spermatocyte undergoes the first meiotic division, it results in the formation of two equal, haploid cells known as secondary spermatocytes, each containing only 23 chromosomes.
(e) Secondary spermatocytes proceed to undergo the second meiotic division, giving rise to four equal, haploid spermatids.
(f) Spermatids are transformed into spermatozoa (sperms) through the process known as spermiogenesis.
Now, let's see the diagram :
Hence, the correct sequence of spermatogenic stages culminating in the formation of sperm in a mature human testis is:
Spermatogonia - Primary spermatocytes - secondary spermatocytes - spermatids - spermatozoa
So, the correct option is (D) : (D), (E), (A), (B), (C).
The prisoners in the concentration camps in World War-II had lost faith in the future. Being in the camp, I felt disgusted with the state of affairs and I forced my thoughts to turn to another subject. ”Suddenly, I saw myself standing on the platform of a well-lit, warm and pleasant lecture room. In front of me, the attentive audience were seated in comfortable upholstered seats. I saw myself giving a lecture on hope, optimism, and resilience under difficult circumstances.” Suddenly, all that oppressed me stopped giving me pain and distress. This practice was so impactful that I could succeed in rising above the situation and the sufferings of the moment.”
Just as individuals compare themselves with others in terms of similarities and differences with respect to what they have and what others have, individuals also compare the group they belong to with groups of which they are not a member. It has been found that groups are more likely to take extreme decisions than individuals alone. Suppose there is an employee who has been caught taking a bribe or engaging in some other unethical act. His/her colleagues are asked to decide what punishment he/she should be given. They may let him/her go scot-free or decide to terminate his/her services instead of imposing a punishment which may commensurate with the unethical act he/she had engaged in. Whatever the initial position in the group, this position becomes much stronger as a result of discussions and interaction in the group.
Reproduction in human beings involves the fusion of male and female gametes that produces in their reproductive system.
The male reproductive system comprises:
The female reproductive system is active before, during, and after fertilization as well. It comprises the following parts: