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 |
|---|---|---|---|
| 39524 | 2020-09-18 20:05:03 | 111.93 | 97% |
| 34725 | 2020-07-05 00:50:47 | 119.13 | 98% |
| 32061 | 2019-08-30 13:29:22 | 117.16 | 98% |
| 31318 | 2019-08-07 19:08:59 | 110.97 | 98% |
| 28184 | 2019-06-29 13:02:48 | 107.38 | 97% |
| 27335 | 2019-06-20 21:22:43 | 100.05 | 98% |
| 24475 | 2019-05-19 19:21:19 | 101.77 | 97% |
| 22251 | 2019-04-05 19:34:05 | 100.89 | 97% |
| 9877 | 2018-10-31 19:42:32 | 72.41 | 96% |
| 5472 | 2018-09-25 17:48:23 | 59.12 | 94% |
| 3185 | 2018-09-08 22:04:37 | 58.13 | 95% |