Somatomedins are released from the liver in response to plasma levels.

Correct Answer: A

Rationale: Elevated GH triggers liver somatomedin (IGF-1) release.

Correct Answer: D

Rationale: Somatostatin is secreted by D (delta) cells in the pancreatic islets to regulate insulin and glucagon secretion.

Correct Answer: C

Rationale: Insulin and somatostatin both inhibit glucagon release from A cells. Insulin has disulfide bonds, somatostatin does not; only insulin causes K^+ uptake.

Correct Answer: D

Rationale: Cholesterol inhibits HMG-CoA reductase, is esterified by ACAT, and downregulates LDL receptors via SREBP, making all statements true.

Correct Answer: C

Rationale: Glucose uses Na^+-dependent SGLT1 for luminal uptake; fructose uses GLUT5 (Na^+-independent). Absorption is mainly in the jejunum.