試題詳解

31. Which of the following is the most distinguishing difference between a purine and a pyrymidine
(A) purines are found in DNA while pyrimidines are found in RNA
(B) purines have nitrogens in the rings while pyrimidines do not
(C) pyrimidines have nitrogens in the rings while purines do not
(D) purines are double ring structures while pyrimidines have a single ring