Where can you find RNA nucleotides ?
This produces an RNA molecule from 5 ' → 3 ' , an exact copy of the coding strand ( except that thymines are replaced with uracils , and the nucleotides are composed of a ribose ( 5 - carbon ) sugar where DNA has deoxyribose ( one fewer oxygen atom ) in its sugar - phosphate backbone ) .mRNA transcription can involve multiple RNA polymerases on a single DNA template and multiple rounds of transcription ( amplification of particular mRNA ) , so many mRNA molecules can be rapidly produced from a single copy of a gene .