DNA and RNA are examples of which macromolecule?

• A. Lipids
• B. Nucleic Acids
• C. Carbohydrates
• D. Proteins

Answer: (B)

DNA and RNA are nucleic acids, the polymers built from nucleotide units. Each nucleotide has a sugar, a phosphate, and a nitrogenous base, and these monomers link to form a long sugar–phosphate backbone with the bases sticking out. This structure lets nucleic acids store and transmit genetic information and, in the case of RNA, help express it. DNA uses deoxyribose and bases A, T, C, G (thymine), while RNA uses ribose and bases A, U, C, G (uracil). They differ from lipids (not built as repeating monomers and mainly used for energy storage and membranes), carbohydrates (polymers of sugars used for energy and structure), and proteins (polymers of amino acids with diverse functions).