In the process of transcription (i.e. copying of genetic information from one strand of the DNA into RNA) in eukaryotes, the RNA polymerase I transcribes rRNA - 28S, 18S and 5.8S. On the other hand, tRNA, 5srRNA and snRNAs are transcribed by RNA polymerase III. RNA polymerase II transcribes precursor of mRNA, hnRNA.