What forms the vaginal lining?

Correct Answer: A

Rationale: The vaginal lining is primarily formed by squamous epithelium. Squamous epithelium is the correct answer because it is the type of epithelium that lines the vaginal canal. Stratified epithelium consists of multiple layers and is not the primary type found in the vaginal lining. Vascular connective tissue and muscle coat are not the main components of the vaginal lining, making them incorrect choices.

Correct Answer: D

Rationale: The correct answer is D. During the menstrual phase of the menstrual cycle, the endometrium is shed up to the basal layer. This shedding occurs as a result of decreased levels of estrogen and progesterone, leading to the breakdown and subsequent shedding of the endometrial lining. Choice A, ovulation, is incorrect as ovulation is the release of an egg from the ovary, which occurs during the mid-cycle. Choice B, regenerative, is incorrect as it does not specifically refer to the phase where the shedding of the endometrium occurs. Choice C, secretory, is incorrect as it refers to the phase where the endometrium thickens in preparation for possible implantation of a fertilized egg, not shedding.

Correct Answer: C

Rationale: The correct answer is C: Mammary glands. The mammary glands are the specific glands in the breast responsible for producing milk. Sebaceous glands (choice A) are oil-producing glands in the skin, racemose glands (choice B) are not a recognized term, and axillary glands (choice D) refer to glands found in the armpit region, not the breast.

Correct Answer: A

Rationale: The correct answer is A: 250,000. At birth, there are approximately 250,000 primordial follicles in the cortex of each ovary. These primordial follicles represent the reserve of oocytes that a female will have throughout her reproductive life. Choice B, 200,000, is incorrect as the number is higher. Choices C and D, 150,000 and 100,000 respectively, are also incorrect as they underestimate the actual number of primordial follicles present at birth.

Correct Answer: D

Rationale: After fertilization, the zygote undergoes cell division through the process of mitosis. Mitosis is the type of cell division that results in two daughter cells with the same number of chromosomes as the parent cell. Choice A, binary fission, is a form of asexual reproduction in prokaryotes, not the process that occurs after fertilization in multicellular organisms. Choice B, meiosis, is a type of cell division that leads to the formation of gametes with half the number of chromosomes, not the process that occurs after fertilization. Choice C, budding, is a form of asexual reproduction seen in some organisms like yeast, but it is not the process of cell division after fertilization.