Mutation is the alteration or change that occurs to the sequence of a gene caused by a mutagen (chemicals) or spontaneously-induced. Depending on how the mutation occurs, it is of different types. The mutation shown in this question is as follows:
ATCGGCTTAACG to ATCGGCTAAACG
This type of mutation is called SUBSTITUTION MUTATION. Substitution mutation is a type of mutation that involves the replacement of one or more nucleotide base by another. In this original sequence; ATCGGCTTAACG, the eight base T was replaced by base A in the sequence, hence, it is a substitution mutation.
