Describe the theory of endosymbiosis as proposed by Lynn Margulis

Describe the theory of endosymbiosis as proposed by Lynn Margulis;

(1) describe the theory in general terms; (2) describe what chloroplasts and mitochondria produce in eukaryotic cells (the specific chemical that is produced by electron transport systems in both cases), (3) provide three details from cell biology that support the theory. Cite 3 different  references.