Mitochondria and chloroplasts display similarities with bacteria that led to the endosymbiont theory. This theory states that an early ancestor of eukaryotic cells engulfed an oxygen-using non-photosynthetic prokaryotic cell. Eventually, the engulfed cell formed a relationship with the host cell in which it was enclosed, becoming an endosymbiont, a cell living within another cell. Indeed, over the course of evolution, the host cell and its endosymbiont merged into a single organism, a eukaryotic cell with a mitochondrion. At least one of these cells may have then taken up a photosynthetic prokaryote, becoming the ancestor of eukaryotic cells that contain chloroplasts.
Game | Time | WPM | Accuracy |
---|---|---|---|
6237 | 2019-04-20 20:04:59 | 153.10 | 98% |
4939 | 2018-11-24 20:03:26 | 144.80 | 98% |
4017 | 2017-12-13 19:45:25 | 137.30 | 98% |
3525 | 2017-11-19 19:27:13 | 130.44 | 98% |