Prescott's Microbiology 8th Edition by Joanne Willey, Linda Sherwood, Christopher J. Woolverton, Lansing Prescott, John Harley, Donald Klein

Exercise 2

Explain the endosymbiotic hypothesis of the origin of mitochondria, hydrogenosomes, and chloroplasts. List two pieces of evidence that support this hypothesis.

Step 1 of 3

The endosymbiotic hypothesis describes the evolutionary origin of three eukaryotic organelles – mitochondria, chloroplasts, and hydrogenosomes. The idea is that a free-living, membrane-bound, single cellular microorganism invaded another organism. Over time the enveloped microorganism became symbiotic with the other organism, providing an evolutionary advantage. A cell that was invaded by a microorganism that was capable of photosynthesis would provide a novel energy source to the invaded cell.