A nucleotide is the basic unit of DNA.

A nucleotide is the basic unit of DNA.

• A. Amino acid
• B. Chromosome
• C. Nucleotide
• D. Nucleoside

Answer: (C)

DNA is built from nucleotides, each with a deoxyribose sugar, a phosphate group, and a nitrogenous base. These nucleotides connect through phosphodiester bonds to form the long DNA polymer, with the sugar-phosphate backbone providing structure and the bases storing genetic information through base pairing. A nucleoside lacks the phosphate group, so it isn’t the repeating unit of DNA. An amino acid is a protein building block, and a chromosome is a large DNA-containing structure, not the basic unit itself. So, the fundamental repeating unit of DNA is the nucleotide.

DNA is built from nucleotides, each with a deoxyribose sugar, a phosphate group, and a nitrogenous base. These nucleotides connect through phosphodiester bonds to form the long DNA polymer, with the sugar-phosphate backbone providing structure and the bases storing genetic information through base pairing. A nucleoside lacks the phosphate group, so it isn’t the repeating unit of DNA. An amino acid is a protein building block, and a chromosome is a large DNA-containing structure, not the basic unit itself. So, the fundamental repeating unit of DNA is the nucleotide.