The ureteric bud is developed from:

Correct Answer: C

Rationale: Ureteric bud sprouts from the mesonephric duct not urogenital sinus, vesicourethral canal, paramesonephric duct, or cloaca. This origin drives metanephric induction, key for kidney formation, contrasting with unrelated structures.

Correct Answer: B

Rationale: Kidneys maintain acid-base balance by excreting H and reabsorbing HCO₃⁻ e.g., PCT reclaims HCO₃⁻, distal tubule secretes H . Excreting both loses buffer acidosis risk. Reabsorbing H /excreting HCO₃⁻ reverses alkalosis. Reabsorbing both retains acid imbalanced. H excretion/HCO₃⁻ retention distinguishes it, key to pH regulation, unlike dual loss or retention.

Correct Answer: D

Rationale: The trigone is the bladder's three openings two ureters, one urethra (e.g., triangular region). Detrusor is muscle not openings. Rugae are folds not specific. Cortex is kidney not bladder. Trigone's anatomical term distinguishes it, key to bladder structure, unlike muscle or unrelated areas.

Correct Answer: C

Rationale: Filtration based on blood pressure occurs at the glomerulus hydrostatic pressure (~55 mmHg) drives GFR (e.g., renal corpuscle). Collecting duct reabsorbs not filters. Distal tubule adjusts post-filtration. Loop concentrates not pressure-driven. Glomerulus's pressure filtration distinguishes it, key to urine initiation, unlike tubular roles.

Correct Answer: D

Rationale: Most body water (~60%) is in cells intracellular fluid (e.g., ~40 L in 70 kg adult). Plasma is ~3 L small fraction. Lymph is minimal circulatory subset. Tissue fluid (interstitial) is ~15% less than cells. Cellular dominance distinguishes it, critical for hydration, unlike extracellular options.