What hormone is responsible for the thickening of the endometrial lining in preparation for pregnancy?

Correct Answer: B

Rationale: The correct answer is B: Progesterone. Progesterone is responsible for thickening the endometrial lining in preparation for pregnancy by promoting the growth of blood vessels and glands. It also helps maintain the uterine lining to support a fertilized egg. Estrogen (choice A) stimulates the growth of the endometrium but progesterone is crucial for thickening. FSH (choice C) and LH (choice D) are involved in the regulation of the menstrual cycle and ovulation, not specifically in thickening the endometrial lining.

Correct Answer: D

Rationale: The correct answer is D (All of the above) because all three hormones (FSH, LH, and Estrogen) play crucial roles in regulating the menstrual cycle. FSH stimulates the growth of ovarian follicles, LH triggers ovulation and promotes the formation of the corpus luteum, and Estrogen helps in the development and maintenance of the uterine lining. Together, these hormones work in a coordinated manner to ensure the proper functioning of the menstrual cycle. Therefore, selecting all of the above is the correct choice as each hormone is indispensable in the regulation of the menstrual cycle.

Correct Answer: A

Rationale: The primary function of the ovaries in females is to produce eggs, which are essential for reproduction. Ovaries contain structures called follicles that release mature eggs during ovulation. This process is crucial for fertilization to occur. The other choices are incorrect because storing sperm is the function of the male reproductive system, producing estrogen and progesterone is a function of the ovaries but not the primary one, and facilitating fertilization is a process that involves multiple reproductive structures, not just the ovaries. Hence, choice A is the correct answer.

Correct Answer: B

Rationale: The correct answer is B: Provide oxygen and nutrients to the fetus. The placenta acts as a bridge between the mother and fetus, allowing the exchange of oxygen and nutrients necessary for fetal growth and development. It also helps in removing waste products from the fetus. Choices A and D are incorrect as the placenta does not excrete waste products or help in the production of milk. Choice C is incorrect as the placenta does not store the fetus but rather provides essential support and nourishment during pregnancy.

Correct Answer: A

Rationale: The correct answer is A: Prolactin. Prolactin is the hormone responsible for triggering milk production in the mammary glands. It is produced by the pituitary gland in response to the suckling stimulus from a newborn. Oxytocin, on the other hand, is responsible for the ejection of milk from the mammary glands. Estrogen and progesterone play roles in the menstrual cycle and pregnancy but do not directly trigger milk production.