Heteronuclear RNA : In eukaryotes, the RNA formed after transcription of DNA is called hnRNA. It is also called high molecular weight RNA or pre-nuclear RNA or DNA-like RNA. This primary messenger RNA is made up of two types of parts. One of these is called intron. There is no code in it. The second part is called exon which carries the genetic code. Of these, introns are removed by the process of RNA splicing. A nuclear organ called spliceosome helps in this process. After this m-RNA is formed, which takes part in the action of translation.
Small nuclear RNA : Small nuclear RNA (snRNA) is one of the small RNA localized in the nucleus of eukaryotic cell. they are complexed with many proteins to form RNA-protein complexes, termed as small nuclear ribonucleoproteins (snRNPs), in the cell nucleus. they are also called snurps. Small nuclear RNAs (snRNAs) are critical components of the spliceosome that catalyze the splicing of RNA.