Question

Select the correct pair of substituted purines.

• A. Cytosine and thymine
• B. Adenine and guanine
• C. Uracil and cytosine
• D. Guanine and uracil

Answer 1

Answer: (B)

Adenine and guanine are substituted purines, while the rest, i.e. uracil, cytosine and thymine, are substituted pyrimidines.