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 |
|---|---|---|---|
| 400597 | 2022-03-29 11:00:37 | 150.93 | 99% |
| 400410 | 2022-03-28 02:35:09 | 118.28 | 97% |
| 308559 | 2020-09-23 09:12:12 | 126.86 | 98% |
| 308019 | 2020-09-12 02:40:53 | 135.43 | 97% |
| 160590 | 2019-08-12 04:56:56 | 112.58 | 96% |
| 122816 | 2019-05-20 02:11:49 | 130.46 | 98% |
| 114682 | 2019-04-30 16:42:37 | 136.39 | 98% |
| 114681 | 2019-04-30 16:41:05 | 126.66 | 97% |
| 113984 | 2019-04-28 04:18:54 | 102.82 | 96% |
| 113150 | 2019-04-25 01:07:34 | 109.82 | 97% |
| 109675 | 2019-04-16 21:38:12 | 121.64 | 97% |
| 109267 | 2019-04-15 04:19:53 | 106.51 | 96% |
| 108991 | 2019-04-14 22:43:31 | 116.72 | 97% |
| 105780 | 2019-04-06 00:30:57 | 108.95 | 97% |
| 104653 | 2019-04-03 02:56:00 | 99.23 | 96% |
| 92332 | 2019-03-20 20:57:26 | 107.67 | 96% |
| 92331 | 2019-03-20 20:50:07 | 102.75 | 97% |
| 64052 | 2019-02-14 23:35:12 | 109.90 | 97% |
| 57073 | 2019-01-29 21:35:27 | 91.69 | 96% |
| 43962 | 2019-01-01 02:29:26 | 102.14 | 97% |
| 43961 | 2019-01-01 02:27:43 | 99.84 | 96% |
| 39455 | 2018-12-18 17:50:32 | 108.14 | 95% |
| 38241 | 2018-12-14 15:08:24 | 101.70 | 96% |
| 37618 | 2018-12-12 17:45:08 | 116.83 | 97% |
| 27844 | 2018-11-16 06:27:24 | 107.66 | 98% |
| 17152 | 2018-10-18 22:08:54 | 98.55 | 96% |
| 11934 | 2018-09-28 23:27:11 | 109.63 | 97% |