Which term best describes the combination of a sugar, a phosphate group, and a nitrogenous base in nucleic acids?

Which term best describes the combination of a sugar, a phosphate group, and a nitrogenous base in nucleic acids?

• A. Nucleotide
• B. Nucleosome
• C. Nucleic Acid
• D. Nucleoid

Answer: (A)

A nucleotide is the basic building block of nucleic acids. It includes a five‑carbon sugar (deoxyribose in DNA or ribose in RNA), a phosphate group, and a nitrogenous base. These nucleotides link together through phosphodiester bonds to form the long polymers of DNA and RNA, with the sugar–phosphate backbone providing the structural framework and the bases carrying genetic information through their pairing rules. The other terms refer to larger structures or contexts: a nucleosome is DNA wrapped around histone proteins, a nucleic acid is the polymer made of many nucleotides, and a nucleoid is the region in a bacterial cell where DNA is concentrated.

A nucleotide is the basic building block of nucleic acids. It includes a five‑carbon sugar (deoxyribose in DNA or ribose in RNA), a phosphate group, and a nitrogenous base. These nucleotides link together through phosphodiester bonds to form the long polymers of DNA and RNA, with the sugar–phosphate backbone providing the structural framework and the bases carrying genetic information through their pairing rules. The other terms refer to larger structures or contexts: a nucleosome is DNA wrapped around histone proteins, a nucleic acid is the polymer made of many nucleotides, and a nucleoid is the region in a bacterial cell where DNA is concentrated.