Mitochondria and chloroplasts arise from preexisting mitochondria and chloroplasts. Mitochondria and chloroplasts arise from preexisting endomembrane systems. Mitochondria and chloroplasts are synthesized in the nucleus. Mitochondria and chloroplasts are synthesized in ribosomes.
I gave my students this multiple choice question: Which concept supports the endosymbiotic origin of complex, eukaryotic double-membrane structures?

Only one answer is correct among these 4 choices:
- Mitochondria and chloroplasts arise from preexisting mitochondria and chloroplasts.
- Mitochondria and chloroplasts arise from preexisting endomembrane systems.
- Mitochondria and chloroplasts are synthesized in the nucleus.
- Mitochondria and chloroplasts are synthesized in ribosomes.

Could you tell me which one is correct?

Mitochondria and chloroplasts arise from preexisting mitochondria and chloroplasts.