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 |
---|---|---|---|
7090 | 2020-04-01 21:45:54 | 109.45 | 97% |
5922 | 2019-10-29 03:54:01 | 97.99 | 96% |
1576 | 2019-04-22 02:35:30 | 98.56 | 97% |