Fungiform papillae appear as red spots on tongue surface because:

Correct Answer: A

Rationale: Fungiform papillae appear red due to their thin epithelium and rich vascularity in the connective tissue, not because of secondary papillae structure.

Correct Answer: B

Rationale: During active HCl secretion, parietal cells' intracellular canaliculi expand with numerous microvilli, and the tubulovesicular system decreases as it fuses with the canaliculi.

Correct Answer: C

Rationale: Zymogen (chief) cells are located in the body and base of fundic glands, not the neck, and secrete pepsinogen and gastric lipase.

Correct Answer: C

Rationale: Striated ducts are found in salivary glands, not the exocrine pancreas, which has intercalated ducts instead.

Correct Answer: D

Rationale: Pancreatic acinar cells secrete digestive enzymes like amylase and lipase, not pepsinogen, which is from gastric chief cells.