Question

Why do mitochondria have their own DNA?

Answer 1

It’s one of the big mysteries of cell biology. Why do mitochondria—the oval-shaped structures that power our cells—have their own DNA, and why have they kept it when the cell itself has plenty of its own genetic material?

Scientists think that mitochondria were once independent single-celled organisms until, more than a billion years ago, they were swallowed by larger cells. Instead of being digested, they settled down and developed a mutually beneficial relationship developed with their hosts that eventually enabled the rise of more complex life, like today’s plants and animals.