Question

multiple choice question the endosymbiont theory proposes that o the first life forms were quartz - based, as evidenced by quartz crystals from greenland containing organic compounds. o eukaryotic organisms and prokaryotic organisms evolved at the same time. o repeated membrane infoldings gave rise to the eukaryotic endomembrane system. o the mitochondrion and chloroplast organelles of eukaryotic cells originated as free - living bacteria.

Explanation:

The endosymbiont theory posits that mitochondria and chloroplasts in eukaryotic cells originated as free - living bacteria that were engulfed by a host cell and developed a symbiotic relationship.

Answer:

The mitochondria and chloroplast organelles of eukaryotic cells originated as free - living bacteria.