Question

A nucleotide consists of three distinct components. Which of the following correctly identifies all three?

Options

• Purine, pyrimidine, and phosphate group

• Nitrogenous base, ribose sugar, and phosphate group

• Nitrogenous base, pentose sugar (deoxyribose), and phosphate group

• Nitrogenous base, deoxyribose, and amino acid

Answer 1

A nucleotide has three components: a nitrogenous base (which carries information), a pentose sugar (deoxyribose in DNA, a 5-carbon sugar), and one to three phosphate groups. Together, these form the basic structural unit of DNA. The pentose sugar must be deoxyribose specifically, not ribose, to distinguish DNA from RNA.