Mistakes are sometimes made in duplicating or transmitting genetic information. These mistakes are called

Mutation

Explanation:

Mutation is any alteration or change in the genetic sequence of a gene caused by mutagens (substances) or mistakes during replication of genetic sequences.

A mutation occurs in the gene from time to time, although, the cell has protocols in place to put them under control if they occur. However, when DNA or a gene is being copied and transferred to offsprings, there is bound for mistakes called MUTATION to occur.

b brown mice / white sand dunes

helicase, i think thats it