Which phase of the menstrual cycle is characterized by the repair and growth of the endometrium?

Correct Answer: D

Rationale: The correct answer is D: Proliferative phase. During this phase, which occurs after the menstrual phase, the endometrium thickens and becomes more vascularized in preparation for potential implantation of a fertilized egg. This phase is characterized by the repair and growth of the endometrium, making it the correct choice. A: Follicular phase - This phase occurs before ovulation and is primarily focused on follicle development, not endometrial repair and growth. B: Luteal phase - This phase occurs after ovulation and is mainly associated with the formation and maintenance of the corpus luteum, not endometrial repair and growth. C: Menstrual phase - This phase involves shedding of the endometrium, not repair and growth.

Correct Answer: C

Rationale: The correct answer is C: Estrogen. Estrogen is the major hormone responsible for the development of secondary sexual characteristics in females. It promotes breast development, regulates the menstrual cycle, and influences body fat distribution. Progesterone (A) is involved in preparing the uterus for pregnancy. Testosterone (B) is the primary male sex hormone, but it also plays a role in female secondary sexual characteristics. Prolactin (D) is primarily responsible for milk production in females, not the development of secondary sexual characteristics.

Correct Answer: B

Rationale: The correct answer is B: Ovaries. The ovaries are the primary site of estrogen production in females. Estrogens are steroid hormones produced mainly by the developing ovarian follicles. The adrenal gland (A) primarily produces hormones like cortisol and aldosterone, not estrogen. The pituitary gland (C) releases hormones that regulate the ovaries but does not produce estrogen directly. The uterus (D) is the site where the fertilized egg implants and grows during pregnancy, but it does not produce estrogen.

Correct Answer: C

Rationale: The corpus luteum is a temporary endocrine structure formed in the ovary after ovulation. It functions to produce both estrogen and progesterone. Estrogen helps in the growth and development of the endometrial lining, while progesterone maintains the uterine lining for potential implantation of a fertilized egg. The other choices are incorrect because the corpus luteum does not solely produce estrogen (choice A) or progesterone (choice B). Additionally, it does not produce hCG (choice D), which is mainly produced by the placenta during pregnancy.

Correct Answer: A

Rationale: Testosterone is the correct answer because it is the primary male sex hormone responsible for the development of male secondary sexual characteristics such as facial hair, deep voice, and muscle growth. Testosterone is produced by the testes in males. Progesterone (B) is a female sex hormone involved in the menstrual cycle and pregnancy. Estrogen (C) is the primary female sex hormone responsible for the development of female secondary sexual characteristics. FSH (D) is a hormone that stimulates the production of sperm in males and the maturation of eggs in females, but it is not directly responsible for male secondary sexual characteristics.