And notice that this, or this for that matter, is different than the sequence given here. We have serene and theory and we have Alanine and Arginine. So we see that the insertion of the cytosine nucleotide between the 7th and the 8th DNA nucleotide causes a shift in the mRNA reading frame. And this in turn changes the codons that are read by the ribosome. And this changes the sequence of amino acids that are produced on the polypeptide chain. And this result usually leads or produces a nonfunctional protein.