n. A nucleic acid present in all living cells and many viruses, consisting of a long, usually single-stranded chain of alternating phosphate and ribose units, with one of the bases adenine, guanine, cytosine, or uracil bonded to each ribose molecule. RNA molecules are involved in protein synthesis and sometimes in the transmission of genetic information. Also called ribonucleic acid.
A. adenine
U. uracil
C. cytosine
G. guanine