Mutations are the changes produced in the nucleotide sequence of the genome.
There are four main types of mutations - substitution, insertion, deletion, and frameshift.
In a substitution mutation, a given base is changed by another. For example, in the sequence CAAGT, if C replaces G, it is a substitution mutation.
In an insertion mutation, extra-base pairs get inserted in the existing sequence. For example, in the sequence CAAGT, if extra base G gets inserted after C, the new sequence would be CGAAGT.
Both substitution and insertion mutations can thus change the codon and hence, the type of amino acid.
