Which of these DNA mutations is likely to have the greatest effect on the structure of the encoded protein? Justify your answer. •Single base substitution •15 bases base deletion •Insertion of 2 bases

The most serious of these mutations will be the insertion of 2 bases. Becasue the genetic code is read in triplets, a 2 base insetion will alter the reading frame of the code causing a frameshift mutation meaning every amino acid after the site of the mutation will be incorrect. This will cause huge structural changes to the protien. 

Whereas the 15 base deletion will only remove those 5 amino acids, but as a multiple of 3, the remaining sequesnce will be unchanged so the ammount of structual change to the protein will be smaller. A substituation mutation simply swaps one base for another so will only affect 1 amino acid.