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 |
---|---|---|---|
9870 | 2017-11-17 01:06:36 | 150.76 | 99% |
9818 | 2017-11-16 15:36:02 | 136.58 | 99% |
9718 | 2017-11-14 19:07:53 | 133.76 | 99% |
9638 | 2017-11-10 01:17:35 | 124.94 | 98% |