Growth hormone exerts its effects on growth by

Correct Answer: A

Rationale: GH primarily acts via IGFs to promote growth.

Correct Answer: D

Rationale: Exercise stimulates glucagon secretion to mobilize glucose. Somatostatin, glucose, and insulin inhibit it, while ketones have a lesser direct effect.

Correct Answer: B

Rationale: Aldosterone has minor glucocorticoid action but primarily regulates Na^+/K^+ via nuclear receptors, not G-proteins. It responds to hyperkalemia, causes acidic urine, and is protein-bound.

Correct Answer: A

Rationale: Chromium enhances insulin action; its deficiency leads to insulin resistance and glucose intolerance.

Correct Answer: B

Rationale: Colipase, secreted by the pancreas, activates pancreatic lipase by aiding fat digestion; cholera acts extracellularly, B_{12} uses intrinsic factor, and oxalates inhibit Ca2+ absorption.