Like DNA, RNA contains four nitrogenous bases. Three of them are the same as those found in DNA.

In DNA, four bases have been found. They are adenine (A), guanine (G), cytosine (C) and thymine (T). The first three of these bases are found in RNA also but the fourth which is uracil (U) is absent in it. RNA contains cytosine and uracil as pyrimidine bases while DNA has cytosine and thymine.