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 |
---|---|---|---|---|
689. | Ray (iconoclastic) | 87.47 | 98% | 2018-07-04 |
690. | richa (richa69) | 87.47 | 97% | 2020-11-04 |
691. | Roma (useflame) | 87.45 | 97% | 2019-02-12 |
692. | Grandhal (grandhal) | 87.41 | 97% | 2020-02-07 |
693. | Aaron (pikachu3004) | 87.39 | 95% | 2018-03-23 |
694. | PAID ISRAEL (dnatrixene135) | 87.39 | 97% | 2018-01-12 |
695. | Dovey (doveyelliott) | 87.36 | 100% | 2018-11-08 |
696. | Priest (priestmlh) | 87.34 | 96% | 2020-02-02 |
697. | Rick Hojun (facehunt) | 87.33 | 97% | 2018-12-29 |
698. | Jonathan (caoculus714) | 87.33 | 97% | 2017-11-30 |
699. | Andy (andyok) | 87.30 | 99% | 2020-02-08 |
700. | Adam (bsplit) | 87.30 | 98% | 2020-08-08 |
701. | ryan (anonymousboy321) | 87.29 | 95% | 2020-11-19 |
702. | Darko (darkec) | 87.27 | 97% | 2020-06-12 |
703. | triplealpha (knytehawke) | 87.27 | 97% | 2018-06-13 |
704. | K (ainestion) | 87.23 | 96% | 2019-12-02 |
705. | Sian Caleb (promechanics) | 87.22 | 98% | 2020-01-11 |
706. | Victor (susavile) | 87.21 | 98% | 2020-02-10 |
707. | (zesty11) | 87.19 | 96% | 2022-12-09 |
708. | Flip (flip2theleft) | 87.18 | 96% | 2020-05-10 |
709. | Itaxim (arconn_) | 87.18 | 96% | 2019-10-02 |
710. | (scaphism) | 87.17 | 93% | 2019-11-29 |
711. | kane (kanekane) | 87.11 | 96% | 2020-11-07 |
712. | Person (improbhighnotgonnalie) | 87.09 | 97% | 2020-08-18 |
713. | SelfPowered (nawid113) | 87.07 | 98% | 2018-08-18 |
714. | Kevin (hellokev) | 87.03 | 95% | 2020-04-14 |
715. | Jon (ace4896) | 87.01 | 96% | 2020-09-14 |
716. | Tull (torfindel) | 86.98 | 96% | 2017-12-01 |
717. | Deniz (usrbin) | 86.98 | 96% | 2018-05-24 |
718. | poem ⛈️ (storm) | 86.95 | 95.9% | 2019-07-29 |
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 |