Pyrimidines are single-ringed nitrogenous bases that include Uracil, Cytosine, and Thymine.

Which of the following nitrogenous bases have a 1 ringed structure?

Correct answer:

Thymine, cytosine, and uracil are pyrimidines (contain one ring).

What is single ring nucleotide?

Adenine and guanine are purines, which contain a pair of fused rings; cytosine, thymine, and uracil are pyrimidines, which contain a single ring (Figure 4-2).