Peptide hormones are made of protein and are water soluble. They can therefore:

Correct Answer: B

Rationale: Peptide hormones bind to membrane receptors, triggering secondary messengers inside the cell.

Correct Answer: D

Rationale: The countercurrent multiplier in the loop of Henle concentrates urine by moving sodium ions.

Correct Answer: D

Rationale: The pancreas does not secrete pepsin; this enzyme is produced by the stomach to digest proteins.

Correct Answer: A

Rationale: Lacteals are lymphatic capillaries within the villi that absorb dietary fats.

Correct Answer: A

Rationale: Polysaccharides, such as starch and cellulose, are complex carbohydrates that store energy or provide structural support.