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 |
|---|---|---|---|
| 98160 | 2020-06-15 03:13:12 | 82.80 | 98% |
| 94527 | 2020-05-05 04:38:40 | 78.93 | 97% |
| 90899 | 2020-04-01 21:46:44 | 65.10 | 95% |
| 63126 | 2018-09-28 00:30:49 | 72.79 | 96% |
| 62116 | 2018-09-04 22:35:11 | 67.33 | 95% |
| 53216 | 2018-03-19 01:58:16 | 77.16 | 97% |
| 50894 | 2018-01-31 12:12:20 | 73.30 | 97% |
| 46187 | 2017-11-05 20:58:38 | 75.63 | 97% |
| 45240 | 2017-10-21 23:06:05 | 72.06 | 97% |