Introns are the remains of an RNA transcript that do not involve in coding and hence they are trimmed off once the protein is translated from the RNA molecule.
Introns are found more commonly in eukaryotic genomes as compared to bacterial and archaeal genes
Group I introns have an ability to invade tRNA, rRNA and protein through its intervening sequences however their insertion into genes is phenotypically neutral.
Yes, this mechanism being one of importants for the regulatory mechanism in our cells. They use non competetive inhibitors. Example: Synthesis of amino acids, etc.
