Uyini umjikelezo weseli futhi yiziphi izigaba zawo?

El umjikelezo weseli Kuyinqubo eyisisekelo yempilo yamaseli, ewavumela ukuthi akhule, athuthuke futhi ahlukane abe amaseli amantombazane amabili. Lesi simo silawulwa kakhulu futhi silawulwa, kuqinisekisa ukuphindwaphindwa okulungile kwe-DNA kanye nokusatshalaliswa kwama-chromosome. Ukuqonda izigaba zomjikelezo wamangqamuzana kubaluleke kakhulu ocwaningweni lwesayensi nakwezokwelapha, njengoba ukungasebenzi kwawo kungaholela ezifweni ezinjengomdlavuza. Kulesi sihloko, sizohlola⁤ngokuningiliziwe ukuthi kuyini⁤ umjikelezo weseli kanye nezigaba ezisiqambayo, ukuhlaziya izindlela ezilawula isigaba ngasinye kanye nezici eziyinhloko zaso naleso.

Isingeniso kumjikelezo weseli

Umjikelezo umakhalekhukhwini kuyinqubo okuyisisekelo okwenzeka kumaseli e-eukaryotic, okuvumela ukukhula nokuhlukana kwawo kuhlanganisa ukulandelana kwezenzakalo okubandakanya izigaba ezihlukene, kusukela ekuphindaphindweni kofuzo kuya ekuhlukaniseni ama-chromosome abe amaseli endodakazi. Ngalo mjikelezo, amangqamuzana alawula ukukhula kwawo futhi aqinisekise ubuqotho bezakhi zawo zofuzo.

Kuwo wonke yomjikelezo wamaseli, kungabonakala izigaba ezehlukene ezenzeka ngokulandelana okuthile. Lezi zigaba zifaka⁤ isixhumi esibonakalayo, esihlukaniswe ngezigaba ezintathu: isigaba ⁤G1, isigaba se-S⁤, kanye nesigaba se-G2; kanye nesigaba sokuhlukaniswa kwamaseli, esaziwa ngokuthi i-mitosis. Phakathi nesigaba se-G1, amaseli akhula ngokushesha, ahlanganise amaprotheni, futhi aphindaphinde ama-organelles.

Isigaba esilandelayo, isigaba sika-S, sibalulekile, ngoba kungalesi sigaba lapho ukuphindwaphindwa kwe-DNA kwenzeka khona. Phakathi nalesi sigaba, ama-chromosome ayaphindaphinda futhi amakhophi amabili afanayo akhiqizwa. Kamuva,⁤ esigabeni se-G2, ⁢amaseli ayaqhubeka nokukhula futhi alungiselele ukuhlukaniswa kwamaseli. Ekugcineni, isigaba se-mitosis siqukethe ukusatshalaliswa kwama-chromosome kumaseli endodakazi, okuqinisekisa ukuthi iseli ngalinye linekhophi eyodwa yezinto zofuzo.

Incazelo nomqondo womjikelezo weseli

Umjikelezo weseli uyinqubo eyisisekelo eyenzeka kuwo wonke amaseli aphilayo, lapho kwenziwa khona uchungechunge lwezehlakalo ezivumela ukukhula kwamaseli, ukuthuthukiswa, nokuzalana Kuyindlela elawulwa kakhulu elawula ⁤ kokubili ukuhlukaniswa kwamaseli kanye nokuphindaphindwa kwezakhi zofuzo impahla. Umjikelezo weseli uhlukaniswe waba izigaba eziningana ezihlukene, ngasinye esiqala uchungechunge lwezenzakalo ezithile.

Isigaba sokuqala somjikelezo weseli saziwa njengesigaba se-G1 (Igebe 1),⁢ lapho iseli ⁣ lilungiselela ⁣ukuphindaphinda kwe-DNA. Phakathi nalesi sigaba, iseli lenza imisebenzi ehlukahlukene ye-metabolic futhi lihlanganise izingxenye ezidingekayo zesinyathelo esilandelayo. Okulandelayo, isigaba S (ukuhlanganiswa) kwenzeka, lapho i-DNA iphindaphinda futhi ama-chromosome ahlanganiswa, alungiselela ukusatshalaliswa kwawo okulandelayo, bese singena esigabeni se-G2 (I-Gap 2), lapho iseli liqhubeka nokukhula kwalo ukuhlukaniswa kwamaseli.

Ekugcineni, sifinyelela esigabeni ⁤M (mitosis),⁤ lapho iseli lihlukana libe amaseli amantombazane amabili afanayo, ngalinye linenombolo ⁤inani elifanayo lama-chromosome njengeseli likamama langempela. I-Mitosis yakhiwa izigaba ezine: i-prophase, i-metaphase, i-anaphase⁢ ne-telophase. ⁤Isiteji ngasinye sinezici ⁢eziyingqayizivele eziqinisekisa ukuhlukaniswa okulungile kwama-chromosome kanye nokwakheka kwamangqamuzana amantombazane amabili. Uma umjikelezo weseli usuqediwe, amaseli endodakazi angaphinde angene ku-G1 futhi aphinde yonke inqubo, noma angakwazi ukuhlukanisa futhi enze imisebenzi ethile entweni ephilayo.

Imisebenzi nokulawulwa⁤ komjikelezo weseli

Umjikelezo wamangqamuzana uyinqubo ebalulekile “yokukhula nokuzala” kwezinto eziphilayo. Bamba imisebenzi yayo futhi ukulawulwa kuyisisekelo socwaningo lwebhayoloji yamaseli kanye nokuthuthukiswa kwezicelo zezokwelapha. Kuwo wonke umjikelezo wamangqamuzana, amangqamuzana adlula ezigabeni ezihlukene, okuhlanganisa i-interphase kanye nokuhlukana kwamangqamuzana, ngalinye linemisebenzi ethile.

I-Interphase yisigaba eside kunazo zonke somjikelezo weseli futhi ihlukaniswe ngezigaba ezintathu: G1 (isigaba sokukhula), S (isigaba sokuhlanganiswa kwe-DNA) kanye ne-G2 (isigaba sangaphambi kokuhlukaniswa). Ngesikhathi se-G1, iseli liyakhula futhi lenze imisebenzi ye-metabolic. Esigabeni sika-S, i-DNA iyaphindwa ukuze kulungiselelwe ukuhlukaniswa kwamaseli Ekugcineni, ku-G2, iseli lilungiselela ukuhlukana futhi lihlanganise amaprotheni adingekayo kulo.

Ukuhlukaniswa kwamaseli kuhlukaniswe izinqubo ezimbili eziyinhloko: i-mitosis ne-cytokinesis. Ngesikhathi se-mitosis, i-nucleus yengqamuzana ihlukana ibe ama-nuclei amabili afanayo, iqinisekisa ukuthi ingqamuzana ngalinye lendodakazi linezakhi zofuzo ezifanayo njengengqamuzana lomzali. Ngakolunye uhlangothi, i-cytokinesis inqubo lapho i-cytoplasm nama-organelles eselula ahlukaniswa phakathi kwamaseli endodakazi, okuqinisekisa ukuthi womabili anazo zonke izingxenye ezidingekayo ekusebenzeni kwawo.

Ukubaluleka komjikelezo weseli ekuthuthukisweni kweseli nokukhula

Umjikelezo wamaseli uyinqubo eyisisekelo yokuthuthukiswa kwamangqamuzana nokukhula kwezinto eziphilayo. Ngochungechunge lwemicimbi e-odelwe, amaseli anekhono lokuphinda i-DNA yawo futhi ahlukane abe amaseli amantombazane amabili afanayo, okubalulekile ekuvuseleleni nasekulungiseni izicubu, kanye nokukhula nokuthuthukiswa kwezinto eziphilayo.

Ukubaluleka komjikelezo weseli kusemandleni ayo okuqinisekisa ukuthi iseli ngayinye yendodakazi ithola ikhophi enembile yezinto zofuzo zeseli lomzali Lokhu kubalulekile ukuze kugcinwe ubuqotho be-DNA futhi kuvinjwe ukunqwabelana kwamaphutha ofuzo Angaholela. ezifweni noma izinguquko ekuthuthukeni. Ngokulandelayo, umjikelezo wamangqamuzana uphinde ulawule ukwanda kwamangqamuzana, ukuvimbela ukuhlukana okungalawuleki okungaholela ekwakhekeni kwezimila nomdlavuza.

Umjikelezo wamaseli uhlukaniswe izigaba eziningana, ngasinye sazo esifeza umsebenzi othile. Lezi zigaba zihlanganisa i-interphase, eyakhiwe isigaba se-G1, isigaba S kanye nesigaba se-G2, lapho kwenzeka ukuphindaphinda kwe-DNA, kanye nesigaba sokuhlukaniswa kwamaseli noma i-mitosis, ehlukaniswe yaba i-prophase, i-metaphase, i-anaphase ne-telophase. Isigaba ngasinye silawulwa inethiwekhi eyinkimbinkimbi yamaphrotheni namasignali amakhemikhali aqinisekisa ukuqhubeka okulungile komjikelezo kanye nokuhlukaniswa okufanele kwama-chromosome phakathi nokuhlukaniswa kwamaseli.

Incazelo yezigaba zomjikelezo weseli

Umjikelezo weseli ⁢inqubo iseli elihlukana ngayo ukuze likhiqize amaseli amantombazane amabili. Le nqubo⁢ iqukethe izigaba ezimbalwa, ngasinye ⁤ezinezici ezithile nezehlakalo. Okulandelayo, sizochaza izigaba zomjikelezo weseli ngokuningiliziwe.

Isigaba G1 (Igebe 1):

Kulesi sigaba, iseli liyakhula futhi lithuthuke. Ngesikhathi se-G1, amaprotheni ne-RNA adingekayo esinyathelweni esilandelayo somjikelezo weseli ayahlanganiswa. Ukwengeza,⁢ iseli lihlola umonakalo we-DNA ngaphambi kokudlulela esigabeni esilandelayo Uma umonakalo utholwa, izindlela zokulungisa ziyacushwa noma, uma kungenakulungiswa, iseli liyaqaliswa. ukufa kweseli ehleliwe, eyaziwa ngokuthi i-apoptosis.

Isigaba S (Ukuhlanganiswa):

Esigabeni S, i-DNA yeseli iyaphindwa. Ichromosome ngayinye eyimpinda iqukethe ama-chromatid amabili ahlanganiswe yi-centromere. Ngalesi sigaba, umshini wamaselula uhlanganisa imicu emisha ye-DNA ehambisanayo ngokuphindaphinda kwe-semiconservative. Isigaba S sibalulekile ukugcina ulwazi lofuzo kuwo wonke amangqamuzana amantombazane.

Isigaba G2 (Igebe 2):

Esigabeni se-G2, iseli liyaqhubeka nokukhula futhi lilungiselela ukuhlukaniswa kwamaseli. Phakathi nalesi sigaba, amaprotheni adingekayo kanye nama-organelles enziwa ukuze akhe amangqamuzana amantombazane amabili afanayo. Kubuye kuqinisekiswe ukuthi i-DNA yenziwe ikhophi ngendlela efanele nokuthi akukho monakalo ekwakhekeni. Uma inkinga itholwa, izindlela zokulungisa ziyacushwa noma i-apoptosis iqalisiwe ukuze kuvinjelwe ukwanda kwamaseli anokungavamile.

Isigaba se-G1: Ukuqala komjikelezo weseli

Esigabeni se-G1, esaziwa nangokuthi "ukuqala komjikelezo wamaseli," amaseli alungiselela "ukuphindaphinda" kwe-DNA yawo kanye "nokuhlukaniswa kwamaseli." Lesi sigaba siphawula ukuqala komjikelezo wamaseli futhi sibalulekile ukuze kuqinisekiswe ukuphindaphinda nokukhula kwamaseli okulungile.

Phakathi nesigaba se-G1, amaseli enza izinqubo eziningi ezibalulekile. Lokhu kufaka phakathi amaprotheni synthesis kanye nokuqoqwa kwamandla adingekayo emjikelezweni olandelayo. Ngaphezu kwalokho, ukubhekwa nokulawula okuqinile kwenziwa ukuze kuqinisekiswe ukuthi amaseli asesimweni esifanele ngaphambi kokungena esigabeni sika-S, lapho kwenzeka ukuphindaphinda kwe-DNA.

Isici esibalulekile sesigaba se-G1 ukuqinisekiswa kobuqotho be-DNA Uma umonakalo noma amaphutha e-DNA etholwa, amaseli angakwazi ukwenza kusebenze izindlela zokulungisa noma amise umjikelezo weseli ngokuphelele. Lokhu kubalulekile ukuze kuvinjwe ukusabalala kofuzo nokugcina ukuzinza kwezakhi zofuzo kumaseli endodakazi. Phakathi nalesi sigaba, umsebenzi oshubile wokulotshwa kwezakhi zofuzo uyenzeka, okunomthelela ekulungiseleleni konke kweseli esigabeni salo esilandelayo. emjikelezweni weseli.

Isigaba S: I-DNA Replication

Esigabeni sika-S somjikelezo weseli, esaziwa ngokuthi yisigaba sokuphindaphinda kwe-DNA, inqubo ebalulekile yokuphindaphindwa kwezakhi zofuzo kumaseli iyenziwa. Phakathi nalesi sigaba, i-molecule ye-DNA iyaqaqa futhi ihlukane ibe imicu ehambisanayo, okuvumela amakhophi amabili afanayo e-DNA yokuqala ukuba akheke.

Ukuphindaphinda kwe-DNA kuyinqubo enembe kakhulu futhi elawulwayo, ehilela ama-enzyme namaprotheni amaningana akhethekile. Ukuze⁤ kuqinisekiswe ukuthembeka kokuphindwayo, kunendlela yokulungisa iphutha ehlala ihlola ubuqotho bamakhophi asanda kuhlanganiswa.

Ukuphindaphinda kwe-DNA kuqala ezindaweni lapho kuvela khona, lapho kwakheka khona amabhamuza okuphindaphinda. Lawa mabhamuza anda ahambisana ne-molecule ye-DNA, akhe amafoloki amabili okuphindaphinda anemicu eholayo kanye nezintambo ezisalelayo. Imicu ehamba phambili ihlanganiswa ngokuqhubekayo, kuyilapho imicu eleleyo ihlanganiswa ngezingcezu ezimfushane ezibizwa ngokuthi izingcezu ze-Okazaki.

Isigaba se-G2: Ukulungiselela ukuhlukaniswa kwamaseli

Kulesi sigaba somjikelezo weseli, ingqamuzana libhekana nesigaba sokulungiselela esinamandla ngaphambi kokuhlukana kwamaseli. Phakathi nesigaba se-G2, izenzakalo eziningi zamangqamuzana namangqamuzana zenzeka ukuze kuqinisekiswe ukuthi iseli lilungele isigaba esilandelayo, ukuhlukaniswa kwamaseli. Lezi zenzakalo ziqinisekisa ukuthi izinto zofuzo ⁢ziphindwa ngokulungile nokuthi izingxenye zeselula ezibalulekile zisendaweni yazo efanele.

Ezinye zezinqubo ezibalulekile ezenzeka phakathi nesigaba se-G2 zifaka:

• Ukwenziwa kwamaprotheni: Phakathi nalesi sigaba, ingqamuzana ikhiqiza amaprotheni adingekayo ekuhlukaniseni amangqamuzana kanye nokwakhiwa kwama-microtubules, abalulekile enqubweni yokuhlukaniswa kwe-chromosome.
• Iphutha ekuhlolweni: Ngaphambi kokungena esigabeni sokuhlukaniswa kwamaseli, iseli lenza ukuhlola okuphelele ukuze lithole futhi lilungise noma yimaphi amaphutha ezintweni zofuzo Lokhu kuqinisekisa ukuthi ama-chromosome aphindwa kabili ngokunembile, kuncishiswe ukuguqulwa okungaba khona kanye nokushintshashintsha kofuzo.
• Inhlangano yemishini ye-Golgi: Phakathi nesigaba se-G2,⁢ amathuluzi e-Golgi⁣ ahlelwa kabusha ukuze kuqinisekiswe ukusatshalaliswa okulungile kwama-organelles nama-molecule adingekayo⁤ ngokuhlukaniswa kweseli. Lokhu kubalulekile enqubweni ye-cytokinesis, lapho ingqamuzana likamama lihlukana libe amangqamuzana amantombazane amabili ahlukene.

Kafushane, isigaba se-G2 somjikelezo weseli siyisigaba esibalulekile lapho iseli lilungiselela ngokucophelela ukwenza ukuhlukaniswa kwamaseli. Ngezinqubo ezinjengokwakheka kwamaprotheni, ukuhlola amaphutha, nokuhlelwa kabusha kwemishini ye-Golgi, iseli liqinisekisa ukuthi yonke into isendaweni yayo efanele ngaphambi kokungena esigabeni esilandelayo sokuhlukaniswa kwamaseli.

Isigaba M: Isigaba sokuhlukaniswa kwamaseli

Isigaba esingu-M yisigaba seseli lapho ukuhlukana kwamaseli, okwaziwa nangokuthi i-mitosis, kwenzeka. Phakathi nalesi sigaba, ingqamuzana likamama lihlukana libe amaseli amantombazane amabili afanayo, ngalinye linesethi ephelele yama-chromosome. Isigaba esingu-M sibuye sihlukaniswe izigatshana ezimbalwa eziqinisekisa ukwehlukana okuhlelekile nokunembe.

Ama-subphase wesigaba se-M afaka i-prophase, i-metaphase, i-anaphase, ne-telophase. Phakathi ne-prophase, ama-chromosome ayajiya futhi ⁢abonakale ngaphansi kwesibonakhulu. Imvilophu yenuzi iyahlakazeka bese kwakheka ama-spindle microtubules phakathi kwezigxobo zeseli. Ku-metaphase, ama-chromosome aqondana endizeni ye-equatorial yeseli futhi anamathisele kuma-spindle microtubules ku-centromere. ⁢Lokhu kuqondana kuqinisekisa ukuthi iseli ngalinye lendodakazi lithola ikhophi eliphelele le-chromosome ngayinye.

I-Anaphase yisikhathi lapho ama-chromosome ehlukana khona futhi ama-chromatids angudadewabo ahlukana. Lawa ma-chromatid aya ngasezigxotsheni eziphambene zeseli, ngenxa yokufinyela kwama-microtubules okuphotha. Ekugcineni, phakathi ne-telophase, ama-chromosome afinyelela ezigxotsheni eziphambene futhi ancibilike. Imvilophu yenuzi yakha futhi ezungeze ama-chromosome futhi ama-nuclei amabili ahlukene ayaqedwa. Ngakho, isigaba M siyaphetha, sinikeza izigaba ezilandelayo. izigaba zomjikelezo weseli.

Umjikelezo wamaseli kumaseli ajwayelekile namaseli omdlavuza

Umjikelezo wamaseli uyinqubo eyinhloko ekuthuthukisweni nasekukhuleni kwezinto eziphilayo. Emangqamuzaneni avamile, umjikelezo weseli uhlukaniswe izigaba ezine ezihlukene: G1, S, G2, futhi M. Phakathi nesigaba se-G1, iseli lidlula isikhathi sokukhula nokulungiselela ukuphindaphinda kwe-DNA Okulandelayo, phakathi nesigaba S, i-DNA ahlanganiswe futhi aphindeke kabili ukulungiselela ukuhlukaniswa kwamaseli. Khona-ke, esigabeni se-G2, iseli liyaqhubeka nokukhula futhi lilungiselela ukuhlukana. Ekugcineni, esigabeni se-M, ukuhlukaniswa kwe-nucleus nokusabalalisa okulinganayo kwe-DNA kumaseli endodakazi kwenzeka.

Ngakolunye uhlangothi, kumangqamuzana omdlavuza, umjikelezo weseli uyashintshwa. Lawa maseli abhekana nokukhula okungalawuleki kanye nokuhlukana kwamaseli okusheshayo. Ezimweni eziningi, amangqamuzana omdlavuza aphinde agweme ukufa kweseli okuhleliwe, okubizwa ngokuthi i-apoptosis. Ngaphezu kwalokho, bangase bethule ukuguqulwa kofuzo okubavumela ukuba bagweme ukulawulwa kwe-DNA kanye nezindlela zokulungisa Lezi zinguquko kumjikelezo weseli kanye nokulawulwa kokukhula zinesibopho sokuthuthukiswa nokukhula kwezimila ezinomdlavuza.

Kubalulekile ukugqamisa ukuthi ukuqonda umehluko womjikelezo wamaseli phakathi kwamaseli avamile namaseli omdlavuza kubalulekile ekuthuthukisweni kwemithi yokwelapha umdlavuza. ⁢Izidakamizwa ezisetshenziswa⁢ ekwelapheni ngamakhemikhali ngokuvamile ziqondise kumaseli omdlavuza ezigabeni ezithile zomjikelezo weseli, zisizakala ngokuhluka kwawo kumaseli avamile. Ngale ndlela, sifuna ukumisa ukwanda komdlavuza futhi sikhuthaze ukufa kwamangqamuzana okuhleliwe ekwelapheni lesi sifo.

Izinto ezingathinta umjikelezo weseli

Kukhona okumbalwa, okungukuthi, inqubo⁤ lapho⁤ iseli ehlukana futhi ikhiqize amaseli amantombazane amabili. Lezi zici zingabandakanya kokubili izici zangaphakathi kanye nezici zangaphandle, futhi zibe nomthelela omkhulu ekulawuleni nasekulawuleni le nqubo ebalulekile.

Phakathi kwezinto zangaphakathi ezingathinta umjikelezo weseli amaphutha ekuphindaphindeni kwe-DNA. Lawa maphutha angenzeka ngesikhathi sesigaba sokuphindaphinda kwezinto zofuzo futhi angaholela ekuguqukeni kwe-DNA. Lezi zinguquko zingashintsha imiyalelo yofuzo elawula umjikelezo weseli, okuholela ekuguqulweni kwesigqi sawo esivamile futhi kuvuse izifo ezingaba khona njengomdlavuza.

Ngakolunye uhlangothi, izici zangaphandle zingathinta nomjikelezo weseli. Ukuchayeka emisebeni ye-ionizing, njengemisebe ye-ultraviolet evela elangeni noma emisebeni ekhishwa imishini yezokwelapha, kungalimaza i-DNA futhi kuphazamise ukuphindaphinda kwayo okufanele. Ngokufanayo, amakhemikhali athile nobuthi obukhona emvelweni kungaphazamisa izindlela ukulawula umjikelezo weseli, okubangela izinguquko kanye nokungasebenzi kahle kwenqubo yokuhlukaniswa kwamaseli.

Izincomo zokugcina umjikelezo wamaseli onempilo

Umjikelezo wamaseli uyinqubo ebalulekile yokukhula nokuvuselela amaseli emzimbeni wethu. Ukugcina umjikelezo wamangqamuzana onempilo kubalulekile ukuvimbela izifo nokukhuthaza izinga lempilo elihle. Ngezansi ezinye ⁢izincomo zokugcina umjikelezo weseli olungile:

• Yamukela ukudla okulinganiselayo: Ukudla okunomsoco okunomsoco kubalulekile ekusebenzeni kahle komjikelezo wamaseli. Qinisekisa ukuthi ufaka ukudla okufana nezithelo, imifino, amaprotheni angenalutho, nokusanhlamvu okuphelele ekudleni kwakho kwansuku zonke.
• Vivinya umzimba njalo: Ukuzivocavoca umzimba okuvamile akusizi nje kuphela ukugcina isisindo esinempilo, kodwa futhi kukhuthaza ukusebenza kahle kwamaseli. Yenza okungenani imizuzu engu-30 yokuzivocavoca umzimba ngosuku, njengokuhamba, ukugijima, noma ukubhukuda.
• Gwema ukucindezeleka: ⁤ Ingcindezi engapheli ingaba nomthelela omubi ⁤umjikelezo weseli. Zama ukuthola amasu okuphumula akusiza ukuthi unciphise ingcindezi, njengokuzindla, i-yoga, noma ukumane uchithe isikhathi wenza imisebenzi oyithandayo.

Kafushane, ukugcina umjikelezo wamaseli onempilo kuyisihluthulelo sokusebenza kahle komzimba wethu. Landela lezi zincomo futhi uqiniseke ukuthi ugcina indlela yokuphila enempilo yonke ukuze ukhuthaze impilo yamangqamuzana akho futhi uvimbele izifo zesikhathi eside.

Iziphetho ngomjikelezo weseli kanye nokuhambisana kwawo kubhayoloji yamaseli

Sengiphetha, umjikelezo wamaseli uyinqubo ebalulekile kubhayoloji yamaseli evumela ukukhula nokukhiqizwa kabusha kwamaseli. Ngochungechunge lwezigaba ezincikene, amaseli ayahlukana futhi aphindaphindeke, aqinisekise ukuzalaniswa kwezinto eziphilayo ezinamangqamuzana amaningi kanye nokushintshwa kwamaseli alimele noma afile. Lo mjikelezo ulawulwa kakhulu futhi ulawulwa yizinqubo ezihlukahlukene, okuhlanganisa izici zokukhula kanye namaprotheni okulawula.

Ukuhambisana komjikelezo weseli kubhayoloji yamaseli akunakuphikwa. Ngenxa yale nqubo, izinto eziphilayo zingakhula, zithuthukise futhi zigcine i-homeostasis yazo. Ngaphezu kwalokho, umjikelezo weseli nawo ubalulekile ekulungiseni izicubu ezilimele nokuvuselelwa kwamangqamuzana awonakele. Ngaphandle komjikelezo wamaseli owanele, izifo ezinjengomdlavuza zingakhula ngokungalawuleki, njengoba amangqamuzana engeke alandele izindlela zokulawula ezidingekayo ukuze kube nokuhleleka kokuhlukaniswa kwamaseli.

Kafushane, ucwaningo lomjikelezo weseli lubalulekile⁣ ukuqonda izinqubo zebhayoloji ezingaphansi kokuthuthukiswa nokugcinwa ⁢kwezinto eziphilayo. Ukuphenya izindlela zokulawula umjikelezo wamangqamuzana, kanye nezifo ezihlobene nokungasebenzi kwawo, kusinikeza ukuqonda okubalulekile ekuthuthukisweni kwemithi kanye nokuseshwa kwezindlela zokwelapha ezilwa nezifo ezimbi kakhulu. Umjikelezo wamaseli uyisimangaliso sebhayoloji yamaseli⁤ eqhubeka nokuthakazelisa ososayensi futhi ithembisa ukuqhubeka nokwembula okusha okutholakele esikhathini esizayo.

Imibuzo Nezimpendulo

Q: Uyini umjikelezo weseli?
IMPENDULO: Umjikelezo weseli inqubo lapho iseli lihlukana futhi liphindaphindeke, okuholela kumaseli amantombazane amabili afana ngofuzo.

Q: Yiziphi izigaba zomjikelezo weseli?
A: Umjikelezo weseli uqukethe izigaba ezine eziyinhloko: isigaba se-G1 (I-Gap 1), isigaba sika-S (Ukuhlanganiswa), isigaba se-G2 (I-Gap 2) kanye nesigaba se-M (Mitosis).

Q: Kwenzekani esigabeni se-G1 somjikelezo weseli?
A:⁣ Phakathi nesigaba se-G1, iseli liyakhula futhi lilungiselele ukuphindwaphindwa kwezakhi zalo zofuzo. Kulesi sigaba, ukulotshwa nokuhunyushwa kwezakhi zofuzo ezidingekayo ekusebenzeni okuvamile kwamaselula kwenzeka.

Q: Kwenzekani esigabeni sika-S somjikelezo weseli?
A: Isigaba sika-S yisigaba sokuhlanganiswa, lapho i-DNA yeseli iphindwaphindwa. Ama-chromosome aphindiwe akhiwa ama-chromatid odade amabili ahlanganiswe ne-centromere.

Umbuzo: Kwenzekani esigabeni Umjikelezo wamaseli we-G2?
A: Isigaba se-G2 siyisigaba sokugcina sokulungiselela ngaphambi kokuhlukaniswa kwamaseli Phakathi nalesi sigaba, iseli lilungiselela ukwehlukana nokulungisa noma yimuphi umonakalo we-DNA uyenziwa ngaphambi kokungena esigabeni M.

Q: Yini⁢ eyenzekayo esigabeni ⁤M somjikelezo weseli?
A: Isigaba esingu-M, esaziwa nangokuthi isigaba se-mitosis, isigaba lapho iseli lihlukana libe amaseli amantombazane amabili afanayo. I-Mitosis inezigaba ezine: i-prophase, i-metaphase, i-anaphase, ne-telophase.

Q: Ulawulwa kanjani umjikelezo weseli?
A: Umjikelezo weseli ulawulwa kakhulu uchungechunge lwamaphrotheni okuthiwa ama-cyclins nama-cyclin-dependent kinases (CDKs). ⁢Lawa maphrotheni⁤ asebenza ⁢njengamaswishi e-molecular acupha futhi alawule ukuguquka phakathi kwezigaba ezihlukene zomjikelezo weseli.

Umbuzo: Kungani umjikelezo weseli⁤ ubalulekile?
IMP: Umjikelezo wamangqamuzana ubalulekile ekukhuleni nasekuthuthukisweni kwezinto eziphilayo ezinamangqamuzana amaningi, kanye nasekulungiseni izicubu nokuvuselela amangqamuzana. Ngaphezu kwalokho, ukulawulwa okufanele komjikelezo wamaseli kubalulekile ukuvimbela ukuthuthukiswa kwezifo ezinjengomdlavuza.

Ukuqaphelwa Kokugcina

Kafushane, umjikelezo wamaseli uyinqubo elawulwa kakhulu evumela amaseli ukuthi akhule, aphindaphinde into yawo yofuzo futhi ekugcineni ahlukanise.⁤ Wenziwe⁤ izigaba ezine ezihlukene: isigaba se-G1,⁣ lapho amaseli akhula futhi ⁤ balungiselela ukuphinda kabili; isigaba S, lapho ukwakheka kwe-DNA kwenzeka futhi izakhi zofuzo ziphindaphindwa; isigaba se-G2, lapho amaseli⁤ alungiselela⁢ ukuhlukana; futhi ekugcineni, isigaba esingu-M, ⁤lapho ukuhlukana kweseli ⁣ukukhuluma kahle kwenzeka.

Isigaba ngasinye somjikelezo wamangqamuzana sidlala indima ebalulekile ekuthuthukisweni nasekugcinweni okufanele kwezinto eziphilayo zamangqamuzana amaningi. Umjikelezo weseli yinqubo elawulwa kakhulu uchungechunge lwezindlela zokulawula kanye nezindawo zokuhlola, eziqinisekisa ukuthi amaseli ahlukanisa ngokufanele futhi avimbele ukwanda okungalawuleki. Ngaphezu kwalokho, umjikelezo weseli uphinde uthonywe yizici zangaphandle kanye nezimpawu zemvelo, okuvumela ukujwayela izimo ezishintshayo.

Ngokuqonda okujulile komjikelezo wamangqamuzana nezigaba zawo, intuthuko ebalulekile ifinyelelwe ezindaweni ezifana ne-oncology kanye nokwelashwa kwezakhi zofuzo. Ukucwaninga kwezinqubo ezilawula umjikelezo wamaseli kuye kwaveza okuhloswe ngakho ukwelashwa okusha futhi kwanikeza imibono emisha yokwelashwa kwezifo ezihlobene nokwanda kwamaseli okungalawuleki.

Sengiphetha, umjikelezo wamangqamuzana uyinqubo ebalulekile ekuthuthukisweni nasekugcinweni kwezinto eziphilayo eziningi. Ucwaningo lwayo oluqhubekayo nolunemininingwane luzosivumela ukuba siqonde kangcono izindlela zokukhula nokuhlukana kwamangqamuzana, futhi kuzovula iminyango emisha yokwelashwa kwezifo ezihlobene nokwanda kwamangqamuzana okungavamile. ⁤