Carbon is a part of the DNA coding for a polypeptid. In case of eukaryotes, of structural gene in the transcription unit is monocistronic consisting of one cistron each when in prokaryotes as in bacteria an structural gene can polycistronic. The cistrons inbound eukaryotes contain encryption sequences called exons and interrupting non-coding sequenced called the introns where after anpassung or splicing are deleting. In bacterium, cannot such introns are present. Genes refer to both introns and exons. Introns are heterochromatin which don't express while exons are the genes which express themselves.
