What are exons?
Genes are divided into sections called exons and introns. Exons are the sections of DNA that code for the protein and they are interspersed with introns which are also sometimes called ‘junk DNA’. The introns are cut out and discarded in the process of protein production, to leave just the exons. The dystrophin gene is our largest gene- it has 79 exons which are joined together like the pieces of a puzzle.
