At the center of each of your trillions of cells are intertwined fibers called DNA. One strand comes from Mom and the other, from Dad. But outside the center of a cell are other cellular parts. One of them is the mitochondrion, which serves as the “power plant” of your cell. We have many mitochondria in each of our cells. Each mitochondrion also houses DNA, albeit much smaller and containing fewer genes than nuclear DNA. That DNA is called mDNA, which, as you would expect, scientists named as such to stand for “mitochondrial DNA,” but which might as well also mean “mom DNA,” because ONLY mothers can pass it on to their children.