The main difference between the four nucleotides that make up dna is that they have different

Nitrogenous bases

Explanation:

A nucleotide is made up of three things a sugar entity which can be ribose sugar or deoxyribose sugar, a nitrogenous base, and a phosphate group.

There are four types of nucleotides according to the difference in the nitrogenous base in the nucleotide. Adenine, guanine, cytosine, and thymine are the four different bases. So the main difference between the four nucleotides that make up DNA is that they have different nitrogenous bases.

In DNA adenine makes complementary base pairing with thymine and guanine makes complementary base pairing with cytosine.