Which of the following is true regarding the menstrual cycle?

Correct Answer: C

Rationale: Correct Answer: C - Progesterone levels rise after ovulation to prepare the uterus for pregnancy. Rationale: 1. Progesterone is primarily produced by the corpus luteum after ovulation. 2. Progesterone helps thicken the endometrial lining to support embryo implantation. 3. Rising progesterone levels inhibit further ovulation. 4. If pregnancy occurs, progesterone is vital for maintaining the uterine lining. Summary: A: Incorrect - Ovulation occurs in the middle of the cycle during the follicular phase. B: Incorrect - The follicular phase is characterized by follicle development, not endometrial lining growth. D: Incorrect - FSH levels are high at the beginning of the cycle to stimulate follicle development, but decrease after ovulation.

Correct Answer: C

Rationale: The correct answer is C: Fallopian tube. Fertilization typically occurs in the fallopian tube, where sperm meets the egg. The fallopian tube provides a suitable environment for fertilization to take place due to its proximity to the ovary, where ovulation occurs. Sperm travel through the fallopian tube to reach the egg, and once fertilization occurs, the resulting zygote then travels down to the uterus for implantation. Incorrect answers: A: Uterus - Fertilization does not occur in the uterus as it is the site for implantation of the fertilized egg. B: Ovary - Ovulation occurs in the ovary, but fertilization usually takes place in the fallopian tube. D: Cervix - The cervix serves as the entrance to the uterus and does not play a role in fertilization.

Correct Answer: B

Rationale: Correct Answer: B - Provide oxygen and nutrients to the fetus Rationale: 1. The placenta is the organ that connects the developing fetus to the uterine wall, allowing for the exchange of nutrients, oxygen, and waste products. 2. It contains blood vessels that transport oxygen and nutrients from the mother to the fetus. 3. The placenta also filters out harmful substances and waste products from the fetus. 4. Providing oxygen and nutrients is crucial for the growth and development of the fetus during pregnancy. Summary: A: Incorrect - The placenta does help in removing waste products but its primary function is not excretion. C: Incorrect - While the placenta does support implantation by attaching the embryo to the uterine wall, its main purpose is not implantation. D: Incorrect - While the placenta does produce hormones like estrogen, its primary function is to provide essential nutrients and oxygen to the fetus.

Correct Answer: C

Rationale: The primary function of the seminiferous tubules in males is to produce sperm. Sperm production, known as spermatogenesis, occurs within the seminiferous tubules through a series of cell divisions and maturation processes. This process is essential for male fertility and reproduction. Therefore, choice C is correct. Choice A (Produce seminal fluid) is incorrect because seminal fluid is primarily produced by the seminal vesicles and prostate gland. Choice B (Mature sperm) is partially correct but not the primary function of the seminiferous tubules. While sperm maturation does occur in the epididymis, the main role of the seminiferous tubules is sperm production. Choice D (Secrete testosterone) is incorrect because testosterone is primarily produced by the Leydig cells in the testes, not in the seminiferous tubules.

Correct Answer: A

Rationale: Progesterone is the correct answer as it helps prepare the uterus for pregnancy by thickening the uterine lining to support implantation of a fertilized egg. Estrogen stimulates the growth of the uterine lining. FSH and LH are involved in the regulation of the menstrual cycle and ovulation, not specifically in preparing the uterus for pregnancy.