Why do mitochondria have their own genome? © Getty Images

Why do mitochondria have their own genome?

Mitochondria are tiny chemical factories inside our cells, but the reason their blueprints are a bit different is down to bacteria.

Asked by: Caroline Ellis, Edinburgh

Advertisement

Mitochondria are tiny chemical factories inside our cells. They have several roles, including extracting and storing energy from digested food. But they also have their own DNA, hinting at a once-independent existence. It’s thought that this reflects their origin as bacteria, which formed a symbiotic relationship with organisms about 2.4 billion years ago and then evolved into us.


Advertisement

Subscribe to BBC Focus magazine for fascinating new Q&As every month and follow @sciencefocusQA on Twitter for your daily dose of fun science facts.