Ukuguquguquka kwempilo amaseli - inkathi kusukela ekuzalweni layo division ezimele noma ukufa

Ukuguquguquka kwempilo amaseli - kwenkathi iyunithi zokucathula fudumele buqala ekuhlukaniseni ayo division noma ukufa. Luhlanganisa zonke izinguquko yemvelo ukuthi ibhekane organelles ekuqhubeni imisebenzi yayo.

Kuye inhlangano futhi lunye ejwayelekile yayo cell umjikelezo ingahlala okungenani imizuzu engu-30 no-3 days. Ngokwesibonelo, lapho ebhidliza amaseli e echinoderms umjikelezo wokuphila lesingemaminithi lange-30, futhi epidermis emathunjini e abantu - ngamahora 12. Kukhona nalabo amayunithi ukuziphilisa, okuyinto abahlukanisiwe, okungukuthi, musa kabusha, enza umsebenzi wabo okuhloswe futhi afe - .. okunjalo njengoba kwenzwa striated imisipha zesivikelo sesifuba. Self cell umjikeleto wemphilo zingahlukaniswa zibe nezikhathi ezimbili: interphase, noma inkathi ukukhula mitosis - inkathi division. Interphase kuhlanganisa, ngokulandelana, eziningi izigaba:

1. G1 (postmitotic) - isigaba sokukhula kokuqala. Kulesi sigaba, inhlangano yabantwana bakwa-mRNA, amaprotheni nezinye izingxenye cell.
2. S (zokwenziwa) - kwenzeka ukufanisana DNA, okuholela kabili zofuzo. Ekupheleni isigaba sesibili sesikhungo solwazi efanayo ifomu DNA double helix. Ngamunye imicu ye-deoxyribonucleic acid yakhiwa eyodwa Kuvunguza ubudala, kanti eyesibili - entsha, okuyinto wabunjwa phezu ngesisekelo complementarity.
3. G2 (premitotic) - inqubo yokulungisa, okuhlanganisa ukulungiswa amaphutha enziwe ngesikhathi DNA zamagama esigabeni odlule. Buthelela izakhi, amandla, qhubeka synthesize amaprotheni RNA.

I element ebalulekile ukukhiqizwa kabusha mitotic umjikelezo we cell proliferative noma ngemva G2 iqala ngqo. Kuyinto iqoqo izinqubo ezenzeka aphansi iyunithi isakhi ophilayo komunye division kuze kube komunye umkhawulo futhi yakha isizukulwane esisha osizayo amaseli. Mitosis uhlobo eyinhloko division ukuphathwa kwabathintwayo (abangeyona ukuzala) kwamayunithi aphansi eziphilayo zenuzi.

Ukuguquguquka kwempilo amaseli abalulekile ukuze umzimba, ukuhlinzeka ukuphepha inombolo nomumo wama-chromosomes nobuntu zinhlobo (karyotype) ngamunye, ngakho-ke kubalulekile ukuthi zonke izinkathi division zidlulile ngaphandle kokuphazanyiswa. Mitosis yakhiwa izigaba 4 alandelanayo:

1. Prophase. Phakathi nale nkathi, yilelo nalelo libe nesigaba cell kwenzeka kanye phakathi kwe izigxobo centrioles, okuyinto oxhumene by division uthi lokuphotha. Ekupheleni kwalesi sikhathi nucleoli iba yingxenye yomhlabathi chromosome uqweqwe futhi mfushane, isb kuyinto ukufingqa zabo.
2. Metaphase. isakhiwo Nucleoprotein kuqondaniswe kanye yenkabazwe amaseli kwakhiwa metaphase ipuleti. Kufika constriction eyinhloko-chromosome. Khona-ke, yilowo nalowo kubo sehlukaniswe chromatids ezimbili.
3. Anaphase. Kulesigaba obrazovashiesya Ama-chromosomes e indodakazi ukuthuthela izingongolo ezahlukene, bakuphi flat futhi sokuphumula.
4. Telophase. Ikhishiwe nucleolus kanye division core cytoplasm kwenzeka.

Ngakho, umjikelezo iseli - nesikhathi sokuphila kusukela ekuzalweni kuze iyunithi zokucathula ukufa labaphilayo.