Where does active mitosis take place

Correct Answer: A

Rationale: The correct answer is A: Stratum germinativum. Active mitosis takes place in the stratum germinativum, also known as the basal layer of the epidermis. This layer contains actively dividing cells responsible for skin regeneration. The other choices, B: Stratum granulosum, C: Stratum lucidum, and D: Stratum corneum, are layers of the epidermis where cells are not actively dividing but rather undergoing differentiation and maturation. Therefore, they do not host active mitosis.

Correct Answer: B

Rationale: The correct answer is B: Sebaceous gland. This gland produces sebum, an oily substance that lubricates the skin and hair. It opens into the hair follicle to distribute sebum along the hair shaft. Sweat glands (choice A) release sweat onto the skin surface, not into hair follicles. Perineal glands (choice C) are located in the genital area and do not open into hair follicles. Zeis glands (choice D) are associated with eyelash follicles, not hair follicles in general. Therefore, the sebaceous gland is the only gland among the choices that opens into hair follicles.

Correct Answer: A

Rationale: The correct answer is A: Perineal glands. The perineal glands, also known as apocrine glands, are responsible for producing pheromones that can stimulate sex libido in humans. These glands are located in the genital area and produce a specific scent that can attract potential mates. Sebaceous glands (choice B) are responsible for producing oil to lubricate the skin and hair, but not directly related to sex libido. Sweat glands (choice C) regulate body temperature by producing sweat, but do not play a direct role in provoking sex libido. Choice D is incorrect because not all of the above glands mentioned are related to sex libido; only the perineal glands are directly linked to stimulating sex drive.

Correct Answer: A

Rationale: The correct answer is A: Skin. Vitamin D is synthesized in the skin when it is exposed to sunlight. UV rays convert a form of cholesterol in the skin into Vitamin D. The liver and kidney play roles in converting and activating Vitamin D, but they are not where Vitamin D is initially synthesized. The stomach is not involved in the synthesis of Vitamin D. So, the skin is the correct choice for the synthesis of Vitamin D in the presence of sunlight.

Correct Answer: C

Rationale: The correct answer is C: Conjunctiva. The conjunctiva is a thin, transparent mucous membrane that covers the front surface of the eye and lines the inside of the eyelids. It is the thinnest epidermis as it is only one cell thick, allowing for transparency and protection of the eye. The face, nipples, and lips have thicker epidermis layers compared to the conjunctiva, making them incorrect choices. Thus, the conjunctiva is the correct answer due to its unique thin structure and location.