Mutations are sudden spontaneous random changes that occur in the genetic make up of an organisms. A substitution mutation is a type of mutation that exchanges one base for another, for example a change in a single base such as switching an A to a G). Substitution could cause a change of codon to one that encodes a different amino acid and cause a small change in the protein produced. In the above sequence AAT-CCG-GTG in substitution of a single base