What are the three components of a DNA nucleotide?

What are the three components of a DNA nucleotide?

• A. Phosphate group, Deoxyribose sugar, Oxygen
• B. Nitrogenous base, Ribose sugar, Phosphate group
• C. Phosphate group, Deoxyribose sugar, Nitrogenous base
• D. Sugar, Phosphate, Amino acid

Answer: (C)

A nucleotide in DNA is built from three parts: a deoxyribose sugar, a phosphate group, and a nitrogenous base. The deoxyribose sugar forms the backbone of the DNA strand, the phosphate group links sugars together through phosphodiester bonds to create the chain, and the nitrogenous base (adenine, thymine, cytosine, or guanine) extends from the sugar and pairs with the complementary base on the opposite strand, encoding genetic information. This trio—phosphate group, deoxyribose sugar, and nitrogenous base—captures the essential components of a DNA nucleotide. The presence of deoxyribose distinguishes DNA from RNA (which uses ribose), and there is no amino acid as part of a nucleotide; adding an extra oxygen atom in the sugar would alter it to ribose, not deoxyribose. Likewise, simply having an oxygen or an amino acid does not define a nucleotide.

A nucleotide in DNA is built from three parts: a deoxyribose sugar, a phosphate group, and a nitrogenous base. The deoxyribose sugar forms the backbone of the DNA strand, the phosphate group links sugars together through phosphodiester bonds to create the chain, and the nitrogenous base (adenine, thymine, cytosine, or guanine) extends from the sugar and pairs with the complementary base on the opposite strand, encoding genetic information. This trio—phosphate group, deoxyribose sugar, and nitrogenous base—captures the essential components of a DNA nucleotide. The presence of deoxyribose distinguishes DNA from RNA (which uses ribose), and there is no amino acid as part of a nucleotide; adding an extra oxygen atom in the sugar would alter it to ribose, not deoxyribose. Likewise, simply having an oxygen or an amino acid does not define a nucleotide.