Question

what does a nucleotide consist of?

nitrogenous bases and sugar
a nitrogenous base, a sugar, and a phosphate
a polymer of nitrogenous bases
sugar and phosphates

Explanation:

A nucleotide is the basic building block of nucleic acids (like DNA and RNA). By definition, it consists of three components: a nitrogenous base (such as adenine, thymine, cytosine, guanine, or uracil), a sugar (deoxyribose in DNA or ribose in RNA), and a phosphate group.

• The first option misses the phosphate group.
• The third option is incorrect as a nucleotide is not a polymer of nitrogenous bases (a polymer would be a chain of nucleotides, like a DNA strand).
• The fourth option misses the nitrogenous base.

Answer:

a nitrogenous base, a sugar, and a phosphate