Endosymbiosis Theory

Provide a brief summary, in your own words, on the main concept/ idea regarding the theory.
Do you believe that the evidence/ data presented supports this theory, why or why not?
Feel free to use scientific literature to help support or refute claims on the theory you choose.
When using literature, make sure to include a citation or URL.

Was there any topic that you struggled with understanding about Endosymbiosis? If so, detail your response as to what part was most challenging and why?  (PUT THE ANSWER ONN THE VERY BOTTOM OF THE ESSAY)