What is the primary site of estrogen production in females?

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: 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.

Correct Answer: D

Rationale: The correct answer is D: hCG. Human Chorionic Gonadotropin (hCG) is produced by the placenta after implantation, confirming pregnancy. Estrogen (A) and Progesterone (C) are important hormones in pregnancy but do not specifically confirm it. FSH (B) is Follicle-Stimulating Hormone, which is not directly related to pregnancy confirmation. hCG is the most reliable indicator of pregnancy as its levels rise significantly in early pregnancy, making it the correct choice.

Correct Answer: B

Rationale: The correct answer is B: Stimulates uterine contractions. Oxytocin is a hormone released during childbirth that acts on the uterus to induce contractions, leading to the progression of labor. It plays a crucial role in facilitating the delivery of the baby. The other choices are incorrect because: A: Inhibiting uterine contractions would hinder the progress of labor. C: Oxytocin does not increase progesterone secretion; it primarily acts on the uterus. D: Oxytocin does not reduce fetal heart rate; instead, it helps in the expulsion of the baby by stimulating contractions.

Correct Answer: C

Rationale: The corpus luteum is formed from the ruptured follicle after ovulation. It secretes progesterone to prepare the uterine lining for implantation and maintain pregnancy. This is essential for supporting early pregnancy until the placenta takes over progesterone production. Choices A and D are incorrect as the corpus luteum primarily produces progesterone, not estrogen or stimulates follicle development. Choice B is incorrect as the corpus luteum does not prevent ovulation but rather supports pregnancy post-ovulation.