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 |
---|---|---|---|
66658 | 2018-02-25 23:51:30 | 129.17 | 98% |
64671 | 2018-02-09 14:57:22 | 137.46 | 97% |
61876 | 2018-01-24 19:29:19 | 136.05 | 98% |
57685 | 2017-12-31 16:45:10 | 138.33 | 98% |