What are the smaller repeating molecules that make up a DNA or RNA molecule called?

The smaller repeating molecules that make up DNA and RNA are called nucleotides. Each nucleotide consists of three components: a phosphate group, a sugar molecule (deoxyribose in DNA and ribose in RNA), and a nitrogenous base. In DNA, the nitrogenous bases are adenine, thymine, cytosine, and guanine, while in RNA, they are adenine, uracil, cytosine, and guanine. These nucleotides link together to form the long chains that make up the genetic material.