Approximately how many sperm are normal ejaculated during intercourse.

Correct Answer: C

Rationale: The correct answer is C: 400,000,000. During ejaculation, a healthy male typically releases around 200-500 million sperm cells. Choice A (4,000) and B (40,000) are too low compared to the average sperm count. Choice D (4,000,000) is also significantly lower than the typical sperm count, making it incorrect. Therefore, C is the correct answer as it aligns with the standard range of sperm count during ejaculation.

Correct Answer: C

Rationale: The correct answer is C: labia. The labia minora are two inner folds that cover and protect the vaginal opening. This is because the labia minora are part of the external female genitalia and specifically designed to provide protection to the vaginal opening. A: Uterus - Incorrect. The uterus is a separate organ and is not involved in covering or protecting the vaginal opening. B: Fallopian tubes - Incorrect. The fallopian tubes are part of the reproductive system but are not located near the vaginal opening or involved in its protection. D: Vagina - Incorrect. While the vagina is connected to the vaginal opening, it is not the structure that directly covers and protects it.

Correct Answer: C

Rationale: The correct answer is C because spermatogenesis occurs within the convoluted seminiferous tubules of the testes. This is where sperm cells are produced through a series of cell divisions and maturation processes. Choice A is incorrect as spermatogenesis does not occur at the level of testicular interstitial cells, which are responsible for hormone production. Choice B is also incorrect as Leydig cells are responsible for testosterone production, not sperm production. Choice D is incorrect as spermatogenesis actually begins during puberty, typically around the age of 12-13, not specifically at the age of 14.

Correct Answer: A

Rationale: The correct answer is A because the ejaculatory duct is formed by the joining of the deferent duct (vas deferens) with the seminal vesicle duct. This is important for transporting sperm and seminal fluid towards the urethra for ejaculation. Choice B is incorrect because the ejaculatory duct does not open directly into the urethra; rather, it joins with the urethra. Choice C is incorrect as the ejaculatory duct is not extratesticular; it is located within the prostate gland. Choice D is incorrect as the ejaculatory duct is not located within the testicle; it is formed outside the testicle by the union of other structures.

Correct Answer: D

Rationale: The correct answer is D because the spermatozoon contains the Y sex chromosome, determining male characteristics. Sperm cells are haploid and carry only one set of chromosomes, including either an X or Y sex chromosome. The presence of the Y chromosome leads to the development of male offspring. Choice A is incorrect as sperm cells do not contain somatic chromosomes. Choice B is incorrect as sperm cells contain one pair of sex chromosomes, not just one. Choice C is incorrect because sperm cells can carry either the X or Y sex chromosome, not specifically the X chromosome.