Which association is CORRECT?

Correct Answer: C

Rationale: Macula densa has basal Golgi not PCT (brush), DCT (no brush), or efferent (renin in afferent). This identifies correct pair, key for histology, contrasting with misassociations.

Correct Answer: B

Rationale: The urinary system arises from intermediate mesoderm (nephrogenic cord) not paraxial (somites), lateral plate (body cavities), all, or none. Intermediate mesoderm forms pronephros, mesonephros, and metanephros, driving kidney and ureter development. This distinguishes germ layer roles, critical for embryogenesis, contrasting with non-urinary mesoderm sources.

Correct Answer: B

Rationale: Kidney ascent is driven by lumbar/sacral growth not ureteric elongation (forms collecting system), cap migration, or all; 'b' fits best. This explains positional shift, critical for anatomy, contrasting with mechanical or combined causes.

Correct Answer: D

Rationale: Male urethra has endodermal (vesicourethral, sinus) and ectodermal (glans) origins not just one or mesodermal alone; 'all' fits broadly. This reflects mixed lineage, critical for urethral development, contrasting with single-layer views.

Correct Answer: A

Rationale: Amino acids aren't nitrogenous wastes reabsorbed or metabolized, not excreted (e.g., PCT). Urea, from protein breakdown major waste. Uric acid, from purines excreted. Creatinine, from muscle waste product. Amino acids' conservation distinguishes them, critical for nitrogen reuse, unlike waste products excreted.