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.
—from Campbell Biology AP Edition, a book by Campbell
Active since January 10, 2019.
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| Rank | Username | WPM | Accuracy | Date |
|---|---|---|---|---|
| 1. | police (styrofoam) | 137.21 | 100% | 2022-10-08 |
| 2. | Tyrone (fastesthackertyper) | 90.92 | 100% | 2019-01-10 |
| 3. | ed72 (ed72) | 69.18 | 100% | 2019-08-10 |
| Universe | Races | Average WPM | First Race |
|---|---|---|---|
| Default (English) | 2,850 | 89.33 | October 7, 2017 |
| Instant Death Mode | 3 | 99.10 | January 10, 2019 |
| All TypeRacer Texts | 1 | 76.47 | February 24, 2022 |
| New English Texts | 1 | 108.31 | May 26, 2022 |