Answer:
Explanation:
Mitochondria and Chloroplast contain some Ribosomes which are different from the cytoplasmic ribosomes,These were measured to be 80s,while the Mitochondria and Chloroplasts are 70s.
Furthermore smaller circular DNA were found in theses two organelles,(which are the first DNA outside nucleus).These DNA types are the exact forms found in bacteria.
Thus, it was concluded that if these organelles could contained these genetic materials,they must be bacterial.Therefore chloroplast and mitochondria were ancient bacterial which now live in a mutual exclusive relationships in the larger cells of Eukaryotas(plant and animals).This is the basis of Endosymbiont theory.
That is these organelles live inside(Endo) new host in symbiosis or beneficial association with one another (symbiont).