is uracil purines or pyrimidines
Cytosine, thymine, and uracil are examples for pyrimidine bases. Adenine and guanine are the two purine bases. DNA has adenine, Guanine, cytosine, and thymine bases, whereas RNA has A, G, C, and uracil (instead of thymine).In DNA and RNA, complimentary bases form hydrogen bonds between them.That is adenine: thiamine/ uracil and guanine: cytosine are complimentary to each other.hey have the following structures. In nucleic acids, purine groups make hydrogen bonds with complementary pyrimidine bases. That is adenine makes hydrogen bonds with thymine and guanine makes hydrogen bonds with cytosine. IN RNA, since thymine is absent, adenine makes hydrogen bonds with uracil.