Question

which of the following lists the components of a nucleotide? a a phosphate group, a deoxyribose, a nitrogen - containing base b a phosphate group, a ribose, a nitrogen - containing base c a nitrogen group, a ribose, a phosphate - containing base d a nitrogen group, a deoxyribose, a phosphate - containing base

Explanation:

A nucleotide is composed of three parts: a phosphate group, a pentose sugar (either ribose in RNA or deoxyribose in DNA), and a nitrogen - containing base. Option a lists deoxyribose (which is correct for DNA nucleotides), a phosphate group, and a nitrogen - containing base. Option b has ribose (which is for RNA nucleotides, but the question is about the general components of a nucleotide. However, if we consider DNA nucleotides specifically, deoxyribose is correct. But if we consider the general structure of a nucleotide (as in the basic unit, without specifying DNA or RNA too strictly, but the naming of nucleotides is based on the sugar - deoxyribonucleotides have deoxyribose and ribonucleotides have ribose. But the question is about the components. A nucleotide has a phosphate group, a sugar (either ribose or deoxyribose depending on the nucleic acid), and a nitrogen - containing base. But looking at the options:

• Option c and d have incorrect groupings (nitrogen group is not a part; it should be a nitrogen - containing base and phosphate group).
• Option b has ribose (for RNA nucleotides). But if we assume the question is about DNA nucleotides (as deoxyribose is a key part of DNA nucleotides and is a common example taught), option a is correct.

Answer:

A. a phosphate group, a deoxyribose, a nitrogen - containing base