嘧

嘧啶

mì dìng

pyrimidine C4H4N2

尿嘧啶

niào mì dìng

uracil nucleotide (U, pairs with adenine A 腺嘌呤 in RNA)

胞嘧啶

bāo mì dìng

cytosine nucleotide (C, pairs with guanine G 鳥嘌呤|鸟嘌呤 in DNA and RNA)

胸腺嘧啶

xiōng xiàn mì dìng

thymine nucleotide (T, pairs with adenine A 腺嘌呤 in DNA)