Three properties that support the endosymbiotic theory are that chloroplasts and mitochondria contain a double membrane, each also contains genetic material that are duplicated with a separated cell cycle and both chloroplasts and mitochondria have their own ribosomes.
Endosymbiotic theory is a theory of evolution that eukaryotes came from prokaryotes. Mitochondria and chloroplasts both have the double membranes. Each of them also contain genetic material that are replicated with a separate cell cycle. Both organelles have their own ribosomes.
