Topic summary
Noncoding
Extracted from the Wikipedia article Non-coding DNA.
Noncoding genes
Noncoding genes account for only a few percent of prokaryotic genomes but they can represent a vastly higher fraction in eukaryotic genomes. In humans, the noncoding genes take up at least 6% of the genome, largely because there are hundreds of copies of ribosomal RNA genes. Protein-coding genes occupy about 38% of the genome; a fraction that is much higher than the coding region because genes contain large introns.