Upon fertilization, an oocyte completes its second meiotic division and produces ________.

Correct Answer: C

Rationale: Rationale: Upon fertilization, an oocyte completes meiosis II, resulting in the formation of the ovum and another polar body. The ovum contains the majority of the cytoplasm and organelles needed for fertilization and embryonic development, while the polar body is a small non-functional cell. This process ensures proper distribution of genetic material and cytoplasm. Incorrect Choices: A: The corona radiata and a polar body are structures associated with the ovulated oocyte, not the result of fertilization. B: The morula and blastocyst are early embryonic stages that form after several cell divisions following fertilization, not products of oocyte meiosis. D: The primary oocyte and secondary oocyte are stages of oocyte development before fertilization and are not produced after fertilization.

Correct Answer: A

Rationale: Estrogens stimulate growth of the endometrium during the proliferative phase by promoting cell proliferation and thickening of the endometrial lining. Estrogens also increase blood flow to the endometrium. Progesterone, on the other hand, prepares the endometrium for implantation and supports pregnancy, but does not directly stimulate growth during the proliferative phase. Insulin and testosterone do not have direct roles in stimulating endometrial growth during this phase.

Correct Answer: A

Rationale: The correct answer is A: bulbo-urethral glands. These glands produce a thick, yellowish secretion known as pre-ejaculate or Cowper's fluid. It serves to nourish and activate sperm. The other choices are incorrect because: B: The prostate gland produces a milky fluid that helps with sperm motility. C: The seminal glands (vesicles) produce a fluid that provides energy for sperm. D: The ejaculatory duct is a passageway for semen to leave the body, it does not produce any secretions.

Correct Answer: B

Rationale: The correct answer is B: bulbo-urethral glands. These glands secrete a milky-colored fluid called pre-ejaculate or Cowper's fluid, which lubricates the urethra and neutralizes any acidic urine residue to protect sperm. The other choices are incorrect because the epididymis (A) stores and matures sperm, the prostate (D) secretes a milky fluid that nourishes and protects sperm, and option C is incomplete.

Correct Answer: D

Rationale: The correct answer is D: ectoderm. The primary germ layer that gives rise to structures like the lacrimal glands is the ectoderm, which is one of the three primary germ layers during embryonic development. The ectoderm gives rise to tissues such as the epidermis of the skin, nervous system, and various glands including lacrimal glands. Choice A, areolar glands to the mucosae and associated glands, is incorrect as they are derived from the mesoderm. Choice C, sweat glands, is also incorrect as they are derived from the ectoderm but are not the primary germ layer responsible for lacrimal glands. Choice B, lacrimal glands is the _______, is incorrect as it does not provide a complete statement and is not a primary germ layer.