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 |
---|---|---|---|
51052 | 2020-11-04 10:32:13 | 123.41 | 98% |
42497 | 2019-08-30 09:22:13 | 110.63 | 97% |
35872 | 2019-05-12 16:41:55 | 111.32 | 99% |
29365 | 2018-06-14 15:48:34 | 99.45 | 98% |