How many rings do purine bases have?

Purine bases, which include adenine and guanine, have a structure characterized by a two-ring system. This distinguishing feature of having two fused aromatic rings is what classifies them as purines, setting them apart from pyrimidines, which only have a single ring. The double-ring structure of purines contributes to their stability and ability to participate effectively in base pairing during the processes of DNA and RNA synthesis. Therefore, identifying the number of rings present in purine bases is vital for understanding their role in nucleic acids and overall genetic processes.