RNA, or ribonucleic acid, contains four nitrogenous bases. These are adenine (A), uracil (U), cytosine (C), and guanine (G). Unlike DNA, which has thymine (T) in place of uracil, RNA uses uracil as one of its building blocks.
Each of these bases plays a critical role in the coding, decoding, regulation, and expression of genes. The sequence of these nitrogenous bases in RNA determines the genetic information carried by the RNA molecule, impacting protein synthesis and other cellular functions. In total, the four distinct nitrogenous bases in RNA form the basis for its diverse functions in biological systems.