The diagram shows a section through a villus. Y X What is a function of structure X and of structure Y?

Correct Answer: A

Rationale: Structure X (epithelial cells) absorbs amino acids, while structure Y (goblet cells) secretes mucus.

Correct Answer: B

Rationale: Humans have three pairs of salivary glands (parotid, submandibular, sublingual) that produce saliva containing amylase; not five as originally asserted.

Correct Answer: C

Rationale: Assimilation involves distributing absorbed nutrients to body cells for use.

Correct Answer: C

Rationale: The lamina propria of the hard palate is directly continuous with the periosteum of the underlying bone, providing a firm attachment. Loose areolar tissue is more typical in softer mucosal areas.

Correct Answer: A

Rationale: Filiform papillae have secondary papillae with separate epithelial caps extending from the primary papillae, unlike other papillae types.