Assertion: nucleotide | /r/HasAspect | structure
Facets:
value: with two rings
type: OTHER
Source sentences:
text: Inc. The four nucleotides of DNA are grouped into two "families" based on their chemical structure: the purines, adenine and guanine, have a structure with two rings; and the pyrimidines, cytosine and thymine, have only one ring (Figure 6).