Answer:
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.
Fact, BRCA genes help with cell division in the breast and prostate regions. Therefore, if they are mutated, the cell division process wouldn't function normally and possibly end up in cancer since the BRCA genes tend to be tumor suppressors (cancer is a malignant tumor).
A keystone species refers to the organisms that define the entire ecosystem. These organisms are important because without them the ecosystem will work differently. They are known to be low in functional redundancy that means if these so-called keystone species disappear, there are no other species who can fill in their role. We can protect them by preserving and protecting their natural habitat, avoiding hunting activities especially the organisms that are considered to be critically endangered, planting trees, and proper waste disposal. These are some of the activities that we can do to protect them.