Cytosine organic compound of the pyrimidine family often called a base consisting of a single ring containing both nitrogen and carbon atoms and an amino group.
胞嘧啶：嘧啶族的有机化合物。常被称为基，包含一个单环，内有氮原子和碳原子，还有氨群。
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Uracil -- a pyrimidine found in RNA that base-pares with adenine.
尿嘧啶--核糖核酸中的一种嘧啶，与腺嘌呤形成碱基对。
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Thymine: Organic compound of the pyrimidine family, often called a Base, consisting of a ring containing Both nitrogen and carbon atoms, and a methyl group.