uracil, U

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

• nucleotide — a phosphoric ester of a nucleoside; the basic structural unit of nucleic acids (DNA or RNA)

• ribonucleic acid, RNA — a large nucleic acid molecule found in the nucleus but mainly in the cytoplasm of a cell where it is associated with microsomes; consists of a linear polymer of nucleotides; it transmits genetic information from DNA to the cytoplasm and controls certain chemical processes in the cell