<prompt> Not present in DNA ?UracilThymineCytosineAdenine  <response>: Ans. is a i.e., Uracil Two types of bases are found in nucleotides : i purines and ii pyrimidines. Purines : Two 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 DNAs e and thymine is not found in RNAs. Different major bases with their corresponding nucleosides and nucleotides Base Ribonucleoside Ribonucleotide Adenine A Adenosine Adenosine monophosphate AMP Guanine G Guanosine Guanosine monophosphate GMP Uracil U Uridine Uridine monophosphate UMP Cytosine C Cytidine Cytidine Monophosphate CMP Base Deoxyribonucleoside Deoxyribonucleotide Adenine Deoxyadenosine Deoxyadenosine monophosphate dAMP Guanine Deoxyguanosine Deoxyguanosine monphosphate dGMP Cytosine Deoxycytidine Deoxycytidine monophosphate dCMP Thymine Deoxythymidine Deoxythymidine monophosphate dCMP 