What is the basic structural unit of DNA and RNA consisting of a phosphate, sugar, and nitrogenous base?

What is the basic structural unit of DNA and RNA consisting of a phosphate, sugar, and nitrogenous base?

• A. Amino acid
• B. Nucleobase
• C. Nucleotide
• D. Monosaccharide

Answer: (C)

Nucleotides are the basic building blocks of DNA and RNA, each made of a phosphate group, a five‑carbon sugar (deoxyribose in DNA or ribose in RNA), and a nitrogenous base. The sugar and phosphate form the backbone of the polymer, while the bases protrude inward and pair with complementary bases (A with T in DNA, A with U in RNA, and G with C). Nucleotides link through phosphodiester bonds to form long strands. Other options don’t fit because an amino acid is for proteins, a nucleobase is only the base without the sugar and phosphate, and a monosaccharide is just a sugar without the phosphate and base.

Nucleotides are the basic building blocks of DNA and RNA, each made of a phosphate group, a five‑carbon sugar (deoxyribose in DNA or ribose in RNA), and a nitrogenous base. The sugar and phosphate form the backbone of the polymer, while the bases protrude inward and pair with complementary bases (A with T in DNA, A with U in RNA, and G with C). Nucleotides link through phosphodiester bonds to form long strands. Other options don’t fit because an amino acid is for proteins, a nucleobase is only the base without the sugar and phosphate, and a monosaccharide is just a sugar without the phosphate and base.