The normal testicular temperature necessary for its optimal functioning is around _______ below the normal body temperature:

Correct Answer: A

Rationale: The correct answer is A: 2-3°C below the normal body temperature. Testicles need to be slightly cooler than the body's normal temperature for optimal functioning. This slight decrease in temperature helps in maintaining the viability of sperm production. Choices B, C, and D are incorrect because a greater deviation from the body's normal temperature would be detrimental to sperm production. B: 4-5°C is too much of a decrease, while C: 33-36°C and D: 31-34°C are higher than the normal body temperature, which would hinder sperm production.

Correct Answer: C

Rationale: The correct answer is C: Nucleus pulposus. The nucleus pulposus is the inner gel-like core of the intervertebral disc that provides cushioning and flexibility. It consists of water, proteoglycans, and cells. The annulus fibrosus (choice B) is the outer ring of tough fibrous tissue surrounding the nucleus pulposus. Nucleus fibrosus (choice A) and Annulus pulposus (choice D) are not anatomically correct terms and do not describe the inner part of the intervertebral disc.

Correct Answer: A

Rationale: The failure of closure of the cranial neural pore leads to anencephaly due to the incomplete development of the brain and skull. This results in the absence of a major portion of the brain, skull, and scalp. Hydrocephaly (B) is the abnormal accumulation of cerebrospinal fluid within the brain's ventricles, not caused by the cranial neural pore closure. Hydrocephalus (C) is the same as hydrocephaly. Chiari malformation (D) is a condition where brain tissue extends into the spinal canal, unrelated to the cranial neural pore closure.

Correct Answer: A

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: B

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.