Which of the following is NOT a form of intracellular signaling?

Correct Answer: D

Rationale: Diurnal signaling is not a recognized form of intracellular signaling.

Correct Answer: D

Rationale: Both dense and loose connective tissues contain fibroblasts producing collagen, though dense has more fibers.

Correct Answer: A

Rationale: Neutrophils are the most abundant WBCs (~60-70%), contain enzymes for phagocytosis, and have a short lifespan (~1-2 days).

Correct Answer: C

Rationale: Eosinophils (~1-4% of WBCs) have granular cytoplasm and are abundant in mucosal tissues, releasing cytokines in allergic responses.

Correct Answer: D

Rationale: Anaemia reduces O2 delivery, limiting exercise capacity; cardiac output rises, 2:3-DPG increases.