Underproduction of growth hormone during the growing years produces ______.

Correct Answer: C

Rationale: Low GH in childhood results in pituitary dwarfism, characterized by stunted growth.

Correct Answer: D

Rationale: Glucagon promotes glycogen breakdown, not storage; insulin stores glucose.

Correct Answer: C

Rationale: Pheromones are chemical signals affecting behavior in other individuals of the same species.

Correct Answer: D

Rationale: The hypothalamus controls heart rate, temperature, water balance, and glandular secretions.

Correct Answer: B

Rationale: Excess GH in adults leads to acromegaly, not gigantism (which occurs in childhood).