<prompt> Which of the follow ing is not a pyrimidine -UracilThymineAdenineCytosine  <response>: Ans. is c i.e., Adenine o Two types of bases are found in nucleotides : i purines and ii pyrimidines.Purines : Tw o major purine bases found both in DNAs as well as RNAs are i adenine A and ii guanine G.Pyrimidines : Three major pyrimidine bases are i cytosine C, ii Uracil U and iii Thymine T. Cytosine and uracil are found in RNAs and cytosine and thymine are found in DNAs. Uracil is not found in DNAsQ and thymine is notfound in RNAs. 