Question

which substance is a nucleic acid?
○ amino acid
○ fat
○ polysaccharide
○ rna

Explanation:

To determine which substance is a nucleic acid, we analyze each option:

• Amino acids are the building blocks of proteins, not nucleic acids.
• Fats are lipids, which are a different class of biomolecules from nucleic acids.
• Polysaccharides are complex carbohydrates (e.g., starch, glycogen), not nucleic acids.
• RNA (ribonucleic acid) is one of the two main types of nucleic acids (the other being DNA), so it fits the definition of a nucleic acid.

Answer:

D. RNA