Question

what is the difference between the purines and pyrimidines

Answer 1

Purines have a two ring structure, and pyrimidine has one ring. Purine is the bigger of the two. The Purines in DNA are Adenine and Guanine, the pyrimidines are thymine and cytosine. In RNA the purines are the same as DNA, and they pyrimidines are uracil and cytosine. Uracil is the RNA substitute for thymine. I hope this helps.