With respect to insulin

Correct Answer: D

Rationale: GLUT2 in β-cells allows glucose entry, triggering insulin release via metabolism and Ca²⁺ high capacity, low affinity fits pancreas. Insulin inhibits ketogenesis, not increases release. It's from β-cells, not A (alpha, glucagon). cAMP (e.g., glucagon) doesn't drive insulin glucose metabolism does. GLUT2's role distinguishes it, critical for insulin secretion, unlike ketone, cell, or signaling errors.

Correct Answer: A

Rationale: Insulin increases amino acid uptake into cells, promoting protein synthesis anabolic role. It enhances K⁺ uptake (with glucose), not reduces key in hyperkalemia treatment. Absorption varies by injection site (e.g., abdomen faster than thigh). It inhibits protein catabolism, not increases. Amino acid uptake distinguishes insulin's growth function, critical for metabolism, unlike K⁺, pharmacokinetics, or catabolic claims.

Correct Answer: D

Rationale: Down-regulation occurs when excessive hormone levels reduce target-cell receptor numbers, preventing overstimulation a negative feedback mechanism. 'Receptor recognition' isn't a process, 'sensory adaptation' applies to nerves, and 'paracrine regulation' involves local signaling not receptor adjustment. Though option D isn't listed, context and endocrine principles confirm 'down-regulation' as standard terminology (likely missing due to OCR cutoff). This adaptive response distinguishes endocrine self-regulation, vital for homeostasis, contrasting with static or unrelated mechanisms.

Correct Answer: C

Rationale: Somatotrophs in the anterior pituitary secrete human growth hormone (hGH), driving growth unlike thyrotrophs (TSH), gonadotrophs (LH/FSH), lactotrophs (prolactin), or corticotrophs (ACTH). This cellular specificity distinguishes GH's production, key to skeletal and tissue development, contrasting with other pituitary functions.

Correct Answer: D

Rationale: Glucocorticoids (e.g., cortisol) promote protein/fat breakdown, gluconeogenesis, and immune suppression not increased oxygen, which relates to respiration. 'D' inferred as missing option fits. This distinguishes glucocorticoids' metabolic/stress roles, vital for energy mobilization, contrasting with respiratory functions.