What is the monomer (subunit) of the DNA molecule called?

What is the monomer (subunit) of the DNA molecule called?

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

Answer: (A)

DNA is built from repeating units called nucleotides. Each nucleotide contains three parts: a five-carbon sugar (deoxyribose), a phosphate group, and a nitrogenous base. When nucleotides connect, they form a sugar–phosphate backbone through phosphodiester bonds, and the bases extend outward to pair with their complementary partners (A with T, C with G). This makes the monomer of DNA a nucleotide, the basic building block from which the long DNA polymer is assembled. The other options refer to subunits of different biomolecules: amino acids build proteins, monosaccharides build carbohydrates, and lipids are not organized as repeating monomer units in the same way as nucleotides.

DNA is built from repeating units called nucleotides. Each nucleotide contains three parts: a five-carbon sugar (deoxyribose), a phosphate group, and a nitrogenous base. When nucleotides connect, they form a sugar–phosphate backbone through phosphodiester bonds, and the bases extend outward to pair with their complementary partners (A with T, C with G). This makes the monomer of DNA a nucleotide, the basic building block from which the long DNA polymer is assembled.

The other options refer to subunits of different biomolecules: amino acids build proteins, monosaccharides build carbohydrates, and lipids are not organized as repeating monomer units in the same way as nucleotides.