RNA polymerases:

Expects prokaryotes where all RNA is synthesized through a single RNA polymerase, the nucleus of a eukaryotic cell has three RNA polymerases responsible for transcribing various kinds of RNA.

-  RNA polymerase I (RNA Pol I) is located in the nucleolus and transcribes the18S, 28S and 5.8S rRNA genes.

-   RNA  polymerase II (RNA  Pol  II) is situated  in the nucleoplasm and transcribes protein-coding genes,  to yield pre-mRNA, and  also the genes encoding  small nucleolar  RNAs  (snoRNAs)  included  in rRNA  processing and  small nuclear RNAs  (snRNAs)  included in  mRNA processing, unlike for U6 snRNA.

-  RNA polymerase III (RNA Pol III) is also situated in the nucleoplasm. It transcribes  the  genes for 5S rRNA, tRNA, U6 snRNA, and the 7S RNA related with the signal  recognition particle (SRP) included  in the translocation  of proteins  across the endoplasmic reticulum  membrane.