DNA, RNA, Chromosomes, and Genes


What are the nitrogenous bases of DNA?

The four nitrogenous bases in DNA are adenine (A), thymine (T), cytosine (C), and guanine (G). These are further divided into two types based on their structure: thymine and cytosine (called pyrimidines) have single-ring structures, while adenine and guanine (called purines) have double-ring structures. A double-ring base is always paired with a single-ring base on the opposite strand.


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