5. These bases are of two different types of molecules: purines and pyrimidines. Purines have ___________ ring(s) in their structure, and pyrimidines have _ ring(s) in their structure. 6. The two bases that are purines are _ and ________. These bases are comprised of _ rings. 7. The two bases that are pyrimidines _ and __. These bases are comprised of _ rings. 8. Based on this information, scientist could predict that the base _ pairs with ___ and the base

These bases are of two different types of molecules: purines and pyrimidines. Purines have double carbon-nitrogen ring(s) in their structure, and pyrimidines have single carbon-nitrogen ring(s) in their structure. 6. The two bases that are purines are Adenine and Guanine. These bases are comprised of double rings. 7. The two bases that are pyrimidines are Thymine and Cytosine. These bases are comprised of single rings. 8. Based on this information, scientists could predict that the base Adenine pairs with Thymine and the base Guanine pairs with Cytosine.

The purine and pyrimidine bases both form parts of the components of the nucleic acids. Purines have double C-N ring structures while pyrimidines have a single C-N structure. The purine bases include Adenine and Guanine while the pyrimidine bases include Thymine (or Uracil in RNA) and Cytosine. According to Chargaff's rule, purine (Adenine/Guanine) pairs with pyrimidine (Thymine/Cytosine).