Explain the endosymbiotic theory and summarize the evidence supporting it. Address the following points (3 point):

Definition – What does the endosymbiotic theory propose about the origin of eukaryotic cells?

Key events – Which organelles are believed to have originated through endosymbiosis?

Evidence – Describe at least three pieces of evidence that support the theory and provide one example of a modern eukaryotic organelle that supports this theory.