What is a function of the male reproductive system?

Correct Answer: A

Rationale: The correct answer is A: To manufacture testosterone. The male reproductive system includes testes that produce testosterone, the primary male sex hormone. Testosterone is responsible for the development of male reproductive tissues and secondary sexual characteristics. Progesterone (B) is primarily produced by the female reproductive system, specifically the ovaries. Ova (C) are female reproductive cells produced by the ovaries. Estrogen (D) is the primary female sex hormone produced by the ovaries. Therefore, A is the correct answer as it accurately reflects the function of the male reproductive system in producing testosterone.

Correct Answer: D

Rationale: The correct answer is D: Pleur. The pleura is the double-layered membrane that covers and protects the lungs. The visceral pleura is in direct contact with the lung tissue, while the parietal pleura lines the chest cavity. This protective membrane helps reduce friction during breathing. Plaque (A), Pancreas (B), and Lymph (C) are incorrect choices. Plaque is a buildup of fatty deposits in arteries, not related to the lungs. The pancreas is an organ involved in digestion and hormone regulation, not part of the lung structure. Lymph refers to the fluid and the system that helps the body fight infections, not a membrane covering the lungs.

Correct Answer: C

Rationale: The correct answer is C: Blurred vision. The first symptom of a cataract is typically blurred vision, as the clouding of the lens causes light to scatter, leading to fuzzy or unclear vision. Reduced side vision (A) is not typically the first symptom, vomiting (B) is not associated with cataracts, and double vision (D) is more commonly linked to other eye conditions. Blurred vision is the hallmark initial symptom of cataracts due to the gradual clouding of the lens.

Correct Answer: D

Rationale: Immunotherapy is the correct answer because it uses antibodies or vaccines to boost the body's immune system to target and destroy cancer cells. It specifically targets malignant tumors without harming normal cells. Radiation therapy (A) uses high-energy rays to kill cancer cells, hormone therapy (B) blocks hormones that cancer cells need to grow, and chemotherapy (C) uses drugs to kill rapidly dividing cells, including cancer cells. However, only immunotherapy directly harnesses the immune system to fight cancer cells.

Correct Answer: D

Rationale: The correct answer is D (6). Performing range of motion exercises at least 6 times for each joint helps maintain joint flexibility and prevent stiffness. This number strikes a balance between providing sufficient stimulation for improvement and avoiding overexertion. Choice A (9) may be excessive and could lead to fatigue or strain. Choices B (5) and C (3) may not provide enough repetitions to effectively improve joint mobility. Therefore, option D is the most appropriate for promoting optimal joint health.