What hormone plays a key role in the development of male secondary sexual characteristics?

Correct Answer: A

Rationale: The correct answer is A: Testosterone. Testosterone is the primary male sex hormone responsible for the development of male secondary sexual characteristics such as facial hair, deep voice, and muscle growth. It is produced by the testes and plays a crucial role in male reproductive system function. Estrogen (B) is the primary female sex hormone, Progesterone (C) is involved in the menstrual cycle and pregnancy, and FSH (D) is a hormone that stimulates the production of sperm in males and eggs in females.

Correct Answer: C

Rationale: The correct answer is C: Maintain the uterine lining for implantation. Progesterone plays a crucial role in preparing and maintaining the uterine lining to support the implantation and growth of the fertilized egg. This hormone helps create a suitable environment for the developing embryo by thickening the uterine lining and preventing its shedding. Explanation for other choices: A: Stimulate uterine contractions - This is incorrect as progesterone actually inhibits uterine contractions during pregnancy to prevent premature labor. B: Support the development of the fetus - While progesterone indirectly supports fetal development by maintaining the uterine environment, its primary function is not directly related to fetal development. D: Promote breast development - Progesterone does play a role in breast development during pregnancy, but its primary function is not focused on this aspect.

Correct Answer: B

Rationale: The correct answer is B: FSH (Follicle-Stimulating Hormone). FSH stimulates the Sertoli cells in the testes to promote sperm production. Testosterone (A) is responsible for male characteristics, not sperm production. LH (C) stimulates testosterone production in the testes but does not directly stimulate sperm production. Prolactin (D) is not involved in sperm production in males. Therefore, FSH is the correct choice as it directly stimulates the production of sperm in males by acting on the Sertoli cells.

Correct Answer: B

Rationale: The correct answer is B: It forms a mucous plug to protect the uterus. During pregnancy, the cervix produces a thick mucus plug that seals the opening of the uterus, providing a barrier against infections and protecting the developing fetus. This plug helps prevent bacteria from entering the uterus and causing harm. Choice A is incorrect because the cervix actually closes during pregnancy to protect the developing fetus from infections. Choice C is incorrect because while the cervix may respond to hormonal changes during pregnancy, it does not secrete estrogen to prepare the uterus. Choice D is incorrect because the production of progesterone during pregnancy primarily occurs in the ovaries and the placenta, not the cervix.

Correct Answer: C

Rationale: The myometrium is the muscular layer of the uterus responsible for contractions during labor. It helps in the expulsion of the fetus by contracting and pushing the baby out of the uterus during childbirth. This process is essential for the safe delivery of the baby. A: Facilitating implantation is the role of the endometrium, not the myometrium. B: Providing nutrients to the embryo is the function of the placenta, not the myometrium. D: Secretion of estrogen is primarily carried out by the ovaries, not the myometrium. Therefore, the correct answer is C as the myometrium plays a crucial role in the expulsion of the fetus during labor.