Izigaba mitosis: izici zabo. Okushiwo mitotic cell division

Umjikelezo iseli - isikhathi komunye cell division elandelayo. Kuthatha indawo izigaba ezimbili ezilandelanayo - interphase kanye division efanele. Isikhathi le nqubo kuyahluka kuye ngohlobo amaseli.

Interphase liyinkathi phakathi ezimbili cell, isikhathi kusukela division wokugcina yokufa kwamangqamuzana engokwemvelo noma ukulahleka ikhono ukwehlukana.

Kule nkathi, iseli luyakhula futhi kabili DNA yayo, kanye mitochondria futhi plastids. Ngo interphase sihamba amaprotheni zamagama , kanye nezinye organic compounds. Inqubo kakhulu uye wakwenza zamagama okuboniswe Synthesis interphase. Ngalesi sikhathi, chromatids zenuzi double, lilondolozwe amandla ezizosetshenziselwa ngesikhathi division. Futhi, inani elandayo lezisebenzi cell organelles futhi centrioles.

Interphase ithatha cishe u-90% umjikelezo cell. Ngemva sidlule mitosis, okuyinto kuyindlela eyinhloko nokuhlukana kwamangqamuzana eukaryotic (eziphilayo kabani amaseli aqukethe i-nucleus kwakhiwa).

Ngezinye mitosis, chromosome wafingqa bakha ama-apharathasi ekhethekile, okuyinto unomthwalo ukusatshalaliswa umfaniswano ukwaziswa kwezakhi zofuzo phakathi amaseli akhiwa le nqubo.

Cell division senzeka ngezigaba eziningana. isigaba mitotic libhekene izici ngamunye kanye ubude ezithile.

Izigaba mitosis

Lapho amangqamuzana omzimba ibhekane mitosis elihambisana izigaba mitosis: prophase, metaphase ngemva kokuba lihambe, anaphase, telophase singu mnqamulajuqu.

isigaba mitotic libhekene izici ezilandelayo:

• prophase - zinyamalale imvilophu zenuzi. Esigabeni lesi, i-centrioles washintsha ukuze imijabo esitokisini futhi Ama-chromosomes e wafingqa (ohlangene);
• metaphase - Sebenzisa libhekene Ama-chromosomes e Ubuningi bamahora ohlangene ukuthi yakhiwa chromatids ezimbili enkabazwe (phakathi) cell. Lesi senzakalo ngokuthi plate metaphase. Kungenzeka ukuba uhlole-chromosomes ngesibonakhulu ziboniswa kahle. Ngo metaphase ka mitosis kwenzeka futhi unamathisele komunye umkhawulo lokuphotha imicu centromeres wama-chromosomes komunye umkhawulo - kuya centrioles.
• anaphase - elikhonjisiwe kuyileli ukwehlukana chromosome ku chromatids (ziyahlakazeka zingene izingongolo ezahlukene). Ngakho chromatids abe-chromosomes elehlukile, aqukethe eyodwa kuphela chromatid ngentambo;
• telophase - libhekene decondensation-chromosomes kanye kumiswa emhlabeni chromosome of imvilophi amasha enuzi ngamunye. intambo lokuphotha zinyamalale nucleus avele nucleoli. Ngo telophase futhi cytokinesis ayishiyile, okuyinto is a division of the cytoplasm phakathi amaseli indodakazi. Le nqubo wenziwa izilwane ngenxa ekhethekile cleavage furrow (okhalweni, okuyinto uhlukanisa iseli amabili). Ngo plant cells inqubo cytokinesis cell ipuleti unikezwe eyinkimbinkimbi Golgi.

Asho begazi inqubo mitosis?

Izigaba mitosis lula wadluliswa ngendlela enembile ilwazi zofuzo indodakazi amaseli, kungakhathaliseki inani ukwahlukana. Ngakho ngamunye wabo owamukela oyedwa chromatid esisisiza inombolo ukungaguquguquki lezakhi zofuzo wonke amaseli ukuthi akhiwa sokuhlukanisa. Inikeza ukudluliswa mitosis isethi okusimeme zofuzo.