How does human sperm move?

Correct Answer: A

Rationale: Human sperm moves using flagella, which are whip-like structures that aid in propulsion. Flagella are tail-like structures found in sperm cells and help them swim towards the egg for fertilization. Cilia are shorter, hair-like structures that are not involved in the movement of sperm. Neutrophils are a type of white blood cell involved in the immune response and are not related to sperm locomotion.

Correct Answer: C

Rationale: The correct answer is the Blue shark. Ovoviviparous animals produce eggs that develop inside the body of the parent, and the offspring are born alive. The basking shark does not fall under this category as it is ovoviviparous, meaning it lays eggs that hatch inside the female's body. The bonobo is a separate species and not relevant to the question.

Correct Answer: C

Rationale: The correct description of a normal cervix on speculum examination in a non-pregnant woman of reproductive age is pink, glistening, smooth mucosa of the exocervix, with a small round or fish-mouthed cervical os. This appearance is characteristic of a healthy cervix. Choice A is incorrect as a bright red mucosa is not normal. Choice B is incorrect as multiple small, fluid-filled protrusions suggest a different condition. Choice D is incorrect as a fleshy protrusion through the cervical os is abnormal.

Correct Answer: C

Rationale: The correct answer is C: '4 months.' The risk of endometrial hyperplasia is highest in individuals who do not menstruate for at least 4 months. This prolonged exposure to unopposed estrogen can lead to endometrial hyperplasia. Choices A, B, and D are incorrect because the risk is greatest after at least 4 months of not menstruating, not 2, 3, or 5 months.

Correct Answer: C

Rationale: Estrogen is primarily responsible for the development of female secondary sexual characteristics. Progesterone, while important in the menstrual cycle and pregnancy, is not primarily responsible for secondary sexual characteristics. Testosterone is the primary male sex hormone. Oxytocin is involved in labor, lactation, and social bonding, but not in the development of female secondary sexual characteristics.