The dna sequence reads acgttcatt before a mutation occurs .after the mutation, the mutation ,the dna sequence reads atcgttcatt .whoch type of mutation occurred ?

The type of mutation is Insertion.

By comparing the two DNA sequences (before and after the mutation) one can observe that there is an insertion of a new nucleotide between two nucleotides in the sequence.

A   CG TT CA TT

AT CG TT CA TT.

In genetics, stitches or insertion mutation is the addition of one or more nucleotide base pairs to DNA sequences. This may occur frequently in the regions of asteroids (microsatellite) due to the sliding of DNA polymerase. The size of this mutation may range from the stitching of a single basal pair in the DNA sequence, to stitches a section of the chromosome into another chromosome.

ask your friends for what they got then copy it down if you don't have any friends which is fine than google it or pay the teacher