How are purines distinguished from pyrimidines?
A) Purines are derived from a pair of fused C-N rings, while pyrimidines are derived from a single C-N ring.
B) Pyrimidines are derived from a pair of fused C-N rings, while purines are derived from a single C-N ring.
C) Purines have a carbon-containing ring, while pyrimidines have a nitrogenous ring.
D) Pyrimidines have a carbon-containing ring, while purines have a nitrogenous ring.
E) Purines are found only in DNA, while pyrimidines are found only in RNA.

Question

Quizplus · Accepted Answer

Purines, such as adenine and guanine, are distinguished by their structure consisting of a pair of fused carbon-nitrogen rings, whereas pyrimidines, including cytosine, thymine, and uracil, are characterized by a single carbon-nitrogen ring structure.

How Are Purines Distinguished from Pyrimidines