Two types of chemically similar nucleic acids, DNA (deoxyribonucleic acid) and RNA (ribonucleic acid), are the principal information-carrying molecules of the cell. The bases adenine, guanine, and cytosine are detected in both DNA and RNA while thymine is observed only in DNA, and uracil is located only in RNA. When it comes to defining the nucleic acid-based in the nature of its nitrogen- and carbon-containing ring structure we have the variation that answers the question. While b. Uracil, c. Cytosine, and d. Thymine only contains a single ring, which we call pyrimidines, the biomolecule a. Adenine contains a pair of fused rings that we call purines, the right answer for the question.
