Which base is NOT found in DNA?

The information in DNA is stored as four nucleotides: adenine (A), guanine (G), cytosine (C), and thymine (T). The nucleotides adenine and guanine are classified as purines, while thymine and cytosine are classified as pyrimidines. Purines contain 2 carbon nitrogen ring bases and pyrimidines contain 1 carbon nitrogen base. These nucleotides can be easily remembered with the mnemonic, ‘GCAT PuPy PuPy,’ where ‘G’ and ‘A’ match up with ‘Pu’ (purine) and ‘C’ and ‘T’ match up with ‘Py’ (pyrimidine). RNA replaces thymine with uracil (U) and can be recalled as ‘GCAU PuPy PuPy.’