Question: Do you think chloroplasts used to be free living micro organisms?

Artem Evdokimov answered on 20 Jun 2012:

I personally think that this theory makes good sense. Chloroplasts have independent genomes, specialized membranes that resemble cyanobacterial membranes, and other features that make them pretty clearly related to cyanobacteria! Fun fact: most people can recall that mitochondria and chloroplasts are descendants of bacteria and cyanobacteria, but not many people remember hydrogenosomes 🙂