Nucleotides build into DNA and RNA.

• A. Proteins.
• B. DNA and RNA.
• C. Carbohydrates.
• D. Lipids.

Answer: (B)

Nucleotides are the building blocks of nucleic acids, which are DNA and RNA. Each nucleotide has a sugar, a phosphate, and a nitrogenous base, and these units link by phosphodiester bonds to form long chains with a sugar–phosphate backbone. That polymerization creates the nucleic acids that store and transmit genetic information. Other macromolecules use different monomers: proteins are built from amino acids, carbohydrates from sugar units, and lipids from fatty acids and glycerol. So the statement that nucleotides build into DNA and RNA is exactly describing the formation of these nucleic acids.