Explain how mutations add variation to the genes of a species?

Basically, a DNA is made up of sequences of nucleotide bases (these are the little strands attaching each side of the DNA that you see in the model). These sequences define what features you get, e.g. hair colour, eye colour, etc. But, these can also mutate, forming a DIFFERENT sequence, this will then lead to a different hair color, eye color, etc.

what's the question?

it would be heredity