An Intron is a section of the sequence in an mRNA which is not meant to be part of the end product and will usually be cut out before the mRNA can be translated into a protein. Sometimes the gene gets cut alternatively. A gene can have different functions, depending on which sections gets cut out. It is a smart way for having the same DNA sequence coding for different versions of the genes, so some versions of it can be used in early development, and others versions can be the adult version.
Teaching about Intron