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n. A pyrimidine base, C4H4N2O2, that is an essential constituent of RNA.

n. One of the bases of RNA. It pairs with adenine and is symbolised by U.

n. A colorless compound, prepared by the action of hydrochloric acid on methylmercapto-uracil. It crystallizes in spherical masses of minute needles and melts at 338° C.

n. a base containing nitrogen that is found in RNA (but not in DNA) and derived from pyrimidine; pairs with adenine

"For 40 years, efforts to understand the prebiotic synthesis of the ribonucleotide building blocks of RNA have been based on the assumption that they must have assembled from their three molecular components: a nucleobase (which can be adenine, guanine, cytosine or uracil), a ribose sugar and phosphate."

base    nucleotide   

guanine    cytosine    choline    g-linolenic