what is the one part of the nucleotide that differs

The three parts of a nucleotide are the nitrogenous base, the sugar, and the phosphate group. The nitrogenous base is the part that differs among the four different nucleotides. There are five nitrogenous bases found in the DNA and RNA world: adenine (A), cytosine (C), guanine (G), thymine (T), and uracil (U). Adenine, cytosine, guanine, and thymine are found in DNA molecules, while uracil is found in RNA.