Brian indicates that the mutation is in a gene found in the mitochondrial DNA. What does Brian mean by that and why did he signify mitochondrial DNA

Change occur in the genetic makeup.

Explanation:

Brian means that the change occur in the genetic makeup of the mitochondrial DNA that change the structure as well as the function ability of mitochondria which is responsible for the generation of energy for the cell. The mitochondrial DNA are passed from mother to offspring through the egg cell. He signify mitochondrial DNA because the change occur only in the mitochondrial DNA not in the whole organism's DNA.