The placenta does which of the following?

Correct Answer: C

Rationale: The correct answer is C: The placenta secretes estrogen. The placenta is an endocrine organ that produces hormones, including estrogen, which plays a crucial role in maintaining pregnancy. Estrogen helps in regulating the menstrual cycle, promoting fetal growth, and preparing the body for childbirth. Choices A and B are incorrect because the placenta does not develop from granulosa cells and does not secrete luteinizing hormone. Choice D is incorrect because the placenta does not allow direct mixing of maternal and fetal blood; instead, it facilitates the exchange of nutrients and waste products between the mother and the fetus through a barrier called the placental barrier.

Correct Answer: B

Rationale: Certainly. The correct answer is B: Testosterone. Interstitial cells of the testis, also known as Leydig cells, synthesize and secrete testosterone. Testosterone is the primary male sex hormone responsible for the development of male reproductive tissues and characteristics. Estrogen (A) is primarily produced in the ovaries in females. Human chorionic gonadotropin (hCG) (C) is produced by the placenta during pregnancy. Luteinizing hormone (LH) (D) is secreted by the anterior pituitary gland and stimulates the interstitial cells to produce testosterone.

Correct Answer: B

Rationale: The correct answer is B: Day 14. Ovulation typically occurs around day 14 of a female's menstrual cycle. This is because ovulation is triggered by a surge in luteinizing hormone (LH) which usually happens midway through the cycle. Ovulation marks the release of an egg from the ovary, making conception possible. Days 7, 21, and 24 are not typically associated with ovulation as they are either too early or too late in the menstrual cycle for the surge in LH to occur. It is important to note that the timing of ovulation can vary among individuals and cycles, but day 14 is considered the average for a 28-day menstrual cycle.

Correct Answer: D

Rationale: The correct answer is D: orchiditis. Orchiditis refers to inflammation of the testicle, which is a type of tissue found in the male reproductive system. This condition specifically affects the testicular tissue, leading to pain, swelling, and possible complications. Skeletal muscle (choice A) is not related to the testicle, phimosis (choice B) is a condition of the foreskin, and epithelial tissue (choice C) primarily covers the surface of organs, not the testicle itself. Therefore, orchiditis is the most relevant choice for a condition affecting testicular tissue.

Correct Answer: A

Rationale: The correct answer is A. The hormone produced by the corpus luteum that helps maintain pregnancy is progesterone. After ovulation, the ruptured follicle forms the corpus luteum, which secretes progesterone to support the uterine lining for potential implantation. Choice B is incorrect as cleavage refers to early cell divisions in embryo development. Choice C is incorrect as fertilization is the fusion of sperm and egg. Choice D is incorrect as estrogen is primarily produced by the ovaries.