Intronless genes
An intron, also known as ‘junk’ DNA, is the non-coding part of a gene. Although this part doesn’t directly participate in the expression of one’s genes, it seems that introns are at least involved in the regulation of gene expression.An exon, on the other hand, is a part of a gene whose transcription and subsequent translation (the processes of gene expression) manifests as your phenotype – i.e. your observable characteristics or traits, including your physical appearance and behaviours.