The "endosymbiotic hypothesis" is a concept that explains how eukaryotic cells might have evolved mitochondria and chloroplasts within their cells how plant cells produce usable cellular energy from sunlight why ribosomes are only found in the eukaryotic cytoplasm, never inside an organelle why mitochondria and chloroplasts are so unlike each other why chromosomes are only found inside the nucleus of a eukaryotic cell

The endosymbiotic hypothesis explains that how eukaryotic cells might have evolved chloroplasts and mitochondria within their cells.  

The endosymbiotic hypothesis states that the eukaryotes have developed via a procedure whereby distinct kinds of free-living prokaryotes became assimilated within the bigger prokaryotic cells and ultimately evolved into chloroplasts, mitochondria, and various other organelles.  

answer: b: experiments that showed that all cells are similar in how they metabolize and in their composition

explanation:

i would say it is