Which of the following is a steroid?

Correct Answer: C

Rationale: The correct answer is C: estrogen. Estrogen is a type of steroid hormone derived from cholesterol. Steroids are a specific group of lipids characterized by a particular molecular structure. Estrogen plays a vital role in the development and regulation of the female reproductive system. Choice A, FSH, and choice B, LH, are both peptide hormones, not steroids. Peptide hormones are made up of amino acids and are not derived from cholesterol. Choice D, GnRH, is also a peptide hormone that regulates the release of other hormones in the body, particularly in the reproductive system. In summary, estrogen is the only steroid hormone among the options provided, making it the correct choice.

Correct Answer: D

Rationale: The correct answer is D: Oxygenated blood. Bidder's canal is a part of the male reproductive system and functions to transport oxygenated blood to the testicles. This is essential for maintaining the temperature required for sperm production. Eggs (A) are not transported through Bidder's canal as it is specific to male reproductive functions. Sperms (B) are produced in the testicles but are not transported through Bidder's canal. Ammonia (C) is a waste product and not involved in the circulation within the male reproductive system.

Correct Answer: D

Rationale: The correct answer is D: Ductus epididymis. The straight tubules in the testis lead into the ductus epididymis because the sperm produced in the testis pass through the straight tubules and enter the epididymis for maturation and storage. This is a crucial step in the sperm development process before they are ready for ejaculation. Rationale: - A: Efferent ducts are incorrect because they connect the rete testis to the epididymis and are responsible for transporting sperm from the testis. - B: Afferent ducts are incorrect as they carry sperm from the rete testis to the epididymis. - C: Rete testis is incorrect as it is a network of tubules where the straight tubules converge and connect to the efferent ducts, not directly to the epididymis.

Correct Answer: B

Rationale: The correct answer is B: LH (Luteinizing Hormone) triggers ovulation. Firstly, LH surge stimulates the release of the mature egg from the ovary. Secondly, it plays a crucial role in the development of the corpus luteum, which produces progesterone to prepare the uterus for potential implantation. GnRH (Choice A) is the hormone that stimulates the release of LH and FSH (Choice C) from the pituitary gland, but it does not directly trigger ovulation. Estrogen (Choice D) is involved in the regulation of the menstrual cycle and prepares the uterine lining for implantation but does not directly trigger ovulation.

Correct Answer: B

Rationale: The correct answer is B: Estrogen. Granulosa cells are located in the ovarian follicles and are responsible for producing estrogen, a key female sex hormone. Estrogen plays a crucial role in the menstrual cycle, pregnancy, and development of secondary sexual characteristics. Progesterone is mainly produced by the corpus luteum, testosterone is primarily produced by the testes in males, and aldosterone is synthesized in the adrenal glands. Granulosa cells do not secrete these hormones, making choices A, C, and D incorrect.