Which represents the correct sequence in ascending order of size?

Correct Answer: A

Rationale: Atoms form amino acids, which link into polypeptides, which fold into proteins (smallest to largest).

Correct Answer: B

Rationale: DNA's backbone is alternating phosphate and deoxyribose sugar units.

Correct Answer: D

Rationale: Sebaceous glands are holocrine, releasing entire cells with secretion; others are merocrine.

Correct Answer: A

Rationale: Intercalated discs are unique to cardiac muscle, aiding synchronized contractions.

Correct Answer: C

Rationale: In a non-dividing cell, DNA is in a diffuse, thread-like form called chromatin.