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 October 7, 2017.
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| Rank | Username | WPM | Accuracy | Date |
|---|---|---|---|---|
| 534. | Laggy (thefitfatass) | 92.21 | 98% | 2018-12-23 |
| 535. | (_paperbird_) | 92.21 | 97% | 2019-04-18 |
| 536. | (typeracer_player111) | 92.20 | 97% | 2020-08-30 |
| 537. | aqibm (aqibm) | 92.17 | 96% | 2018-02-19 |
| 538. | (returned) | 92.17 | 97% | 2020-04-02 |
| 539. | (monpre) | 92.17 | 98% | 2020-11-17 |
| 540. | (avtrisal) | 92.13 | 96% | 2020-06-27 |
| 541. | (orionrw) | 92.11 | 97% | 2019-09-13 |
| 542. | (atypicaltypist) | 92.03 | 97% | 2018-03-22 |
| 543. | (trullama) | 92.03 | 97% | 2020-11-19 |
| 544. | (pingu_workman) | 92.02 | 97% | 2020-05-14 |
| 545. | (framed_phoenix) | 92.00 | 97% | 2018-03-31 |
| 546. | (audimka04) | 91.99 | 98% | 2018-08-10 |
| 547. | (cooldude_) | 91.98 | 96% | 2017-10-07 |
| 548. | Matt (matthewjpb) | 91.92 | 97% | 2018-05-25 |
| 549. | (sayake) | 91.91 | 95% | 2018-12-20 |
| 550. | hopeless...wrecked (_navdee... | 91.78 | 98% | 2019-11-27 |
| 551. | (emilybutler122) | 91.74 | 99% | 2019-07-21 |
| 552. | (skilledscott) | 91.69 | 97% | 2017-12-08 |
| 553. | (szymon2410) | 91.64 | 97% | 2017-12-29 |
| 554. | (hyperkinetic) | 91.63 | 98% | 2019-12-16 |
| 555. | (ironhide227) | 91.63 | 97% | 2020-04-11 |
| 556. | Nick (jellywizard) | 91.59 | 98% | 2020-06-25 |
| 557. | (dorrzun) | 91.57 | 96% | 2019-01-29 |
| 558. | Carlos (estevaoima) | 91.51 | 98% | 2017-11-24 |
| 559. | (katierae) | 91.42 | 98% | 2018-08-18 |
| 560. | (belacanlas) | 91.33 | 97% | 2018-12-06 |
| 561. | Rango (chucknorrisauresrex) | 91.32 | 96% | 2019-01-23 |
| 562. | (bull3tf) | 91.28 | 98% | 2018-09-11 |
| 563. | (tsunira) | 91.20 | 95% | 2018-12-21 |
| Universe | Races | Average WPM | First Race |
|---|---|---|---|
| Default (English) | 2,929 | 89.24 | October 7, 2017 |
| Instant Death Mode | 3 | 99.10 | January 10, 2019 |
| New English Texts | 1 | 108.31 | May 26, 2022 |
| All TypeRacer Texts | 1 | 76.47 | February 24, 2022 |