When do the corona radiata cells appear?

Correct Answer: A

Rationale: The corona radiata cells appear at birth because they are a crucial part of the ovum and are present as soon as the ovum is released from the ovary. The other choices are incorrect because corona radiata cells are not formed at 12, 28, or 1 day after birth. They are specifically associated with the ovum and its release during ovulation, making option A the most accurate.

Correct Answer: B

Rationale: The correct answer is B, the uterine tube. Fertilization typically occurs in the uterine tube, also known as the fallopian tube, where the egg and sperm meet and fuse to form a zygote. This is the site where the fertilized egg begins its journey towards the uterus for implantation. The other choices are incorrect because fertilization does not occur in the uterus (A), ovary (C), or pelvic cavity (D). The uterus is where the fertilized egg implants and develops into a fetus, the ovary is where the egg is released during ovulation, and the pelvic cavity is a space that houses reproductive organs but not the site of fertilization.

Correct Answer: C

Rationale: The correct answer is C: Testosterone. Testosterone is the primary male sex hormone produced by the testes. It plays a crucial role in the development of male reproductive tissues and secondary sexual characteristics. Progesterone (A) is a female sex hormone produced in the ovaries, not the testes. Vasopressin (B) is a hormone produced by the pituitary gland, not the testes. "None of the above" (D) is incorrect as testosterone is indeed released from the testes.

Correct Answer: A

Rationale: The correct answer is A: Sperm maturation. The epididymis is a coiled tube where sperm undergo maturation, gaining motility and ability to fertilize an egg. It does not produce sperm (incorrect B), but stores sperm for a short period (incorrect C) before ejaculation. It also does not provide nutrition to sperm (incorrect D).

Correct Answer: A

Rationale: The correct answer is A: Progesterone. After ovulation, the corpus luteum forms from the ruptured follicle and secretes progesterone to prepare the uterus for implantation. Progesterone helps maintain the endometrial lining for potential pregnancy. Choice B, Relaxin, is secreted by the corpus luteum, but its main function is to soften the cervix and pubic symphysis. Choices C and D, LH and FSH respectively, are pituitary hormones involved in the menstrual cycle regulation, not directly secreted by the corpus luteum.