Which of the following is the correct order of the stages of labor?

Correct Answer: A

Rationale: The correct order of the stages of labor is Dilation, Expulsion, Placental (Choice A). Firstly, dilation refers to the opening of the cervix to allow the baby to pass through. Secondly, expulsion is when the baby is delivered. Lastly, the placental stage involves the delivery of the placenta after the baby is born. This sequence is crucial for a safe delivery and recovery. Choices B, C, and D are incorrect because they do not follow the natural progression of labor stages and may lead to complications if followed.

Correct Answer: C

Rationale: The acrosome in sperm contains enzymes that help it penetrate the egg during fertilization. These enzymes break down the outer layer of the egg, allowing the sperm to enter and fertilize it. This makes choice C the correct answer. Choices A and D are incorrect because the acrosome is not responsible for providing energy for movement or producing enzymes for sperm maturation. Choice B is also incorrect as storing sperm is not the primary role of the acrosome.

Correct Answer: A

Rationale: The correct answer is A: Seminal vesicles. Seminal vesicles are responsible for producing the majority of the fluid in semen, contributing to sperm motility and viability. The other choices are incorrect because: B: Epididymis stores and transports sperm; C: Testes produce sperm; D: Vas deferens transports sperm from the epididymis to the urethra.

Correct Answer: A

Rationale: Estrogen is responsible for thickening the endometrial lining during the proliferative phase of the menstrual cycle to prepare for pregnancy. It stimulates the growth and development of the endometrium. Progesterone, not FSH or LH, is responsible for maintaining the endometrial lining after it has been thickened by estrogen. FSH is involved in stimulating the growth of ovarian follicles, while LH triggers ovulation. Therefore, the correct answer is A (Estrogen) as it directly influences the thickening of the endometrial lining for pregnancy preparation.

Correct Answer: B

Rationale: The correct answer is B: hCG. Human Chorionic Gonadotropin (hCG) is produced by the placenta during pregnancy to support the corpus luteum in producing progesterone, which is essential for maintaining the pregnancy. Prolactin (A) is produced by the pituitary gland and stimulates milk production. FSH (C) is a hormone released by the pituitary gland to stimulate egg production in females. Progesterone (D) is produced by the corpus luteum and later by the placenta during pregnancy to support the uterine lining.