The caudal somites migrate to give the following except:

Correct Answer: D

Rationale: Caudal somites form genital tubercle, swellings, external sphincter, and abdominal wall not internal anal sphincter (splanchnic mesoderm). This excludes visceral muscle, key for somitic roles, contrasting with included derivatives.

Correct Answer: A

Rationale: Low blood oxygen triggers erythropoietin release stimulates RBC production (e.g., peritubular cells). Renin responds to pressure not oxygen. Angiotensin is RAAS product not kidney-released. Calcitriol is vitamin D not oxygen-linked. Erythropoietin's hypoxia response distinguishes it, key to oxygenation, unlike pressure or mineral roles.

Correct Answer: C

Rationale: The prostate gland surrounds the male urethra at bladder exit prostatic urethra (e.g., ~20 cm total). Adrenals are kidney-top not urethra. Bulbourethral glands are distal penile urethra. Hilum is kidney not bladder. Prostate's position distinguishes it, key to male anatomy, unlike other glands or sites.

Correct Answer: D

Rationale: Tubular reabsorption primarily occurs in the PCT ~65-70% of filtrate (e.g., Na , water, glucose). Collecting duct adjusts less volume. Distal tubule fine-tunes smaller role. Capsule filters not reabsorbs. PCT's dominance distinguishes it, critical for bulk reclamation, unlike later or filtration sites.

Correct Answer: A

Rationale: PCT (~65% water) and collecting duct (ADH-driven) increase water reabsorption e.g., bulk and regulated recovery. Distal tubule adjusts less water focus. Loop sets gradient not ADH-dependent. PCT/collecting synergy distinguishes it, key to water conservation, unlike partial or gradient-focused pairs.