Iiseli zomzimba wethu kufuneka zahlulwe ngokuqhubekayo ngenkqubo yokwahlulwa kweseli eyaziwa njenge imitosis. Kule nkqubo isuntswana leseli lahlula-hlula ukuvelisa iiseli zeentombi ezimbini. Ezi iiseli zenziwe zifana ngokwemfuza. IMitosis yinxalenye yomjikelo wokwahlula iiseli apho iDNA ekwiseli yeseli yahlulahlula ibe ziiseti ezimbini ezilinganayo zeekromosomes.
Kule nqaku siza kukuxelela yonke into ofuna ukuyifumana malunga ne-mitosis kunye nokubaluleka kwayo.
Yintoni i-mitosis
I-Mitosis yinkqubo yokwahlukana kweseli apho iDNA yenucleus yeseli yahlulwe yangamaqela amabini ukuze yenze ii-chromosomes. Uninzi lwesahlulo seseli esenzeka emzimbeni sibandakanya i-mitosis. Ukwahlulwa kweeseli kubalulekile ukuze sikwazi ukuhlala siphila. Ngexesha irejimeni yophuhliso lweseli, i-mitosis igcwalisa umzimba womzimba ngeeseli zobomi bomzimba. Ukongeza, kuyanceda ukubuyisela iiseli ezindala kunye nezichithwe kwezinye iiseli ezintsha. Ngale ndlela, iiseli ze-eukaryotic eneseli enye enjegwele, izahlulo zemototic yindlela enye yokuvelisa kwakhona.
Injongo ye-mitosis kukuqinisekisa ukuba iseli nganye yokukhanya inokufumana iseti epheleleyo yesiphene se-chromosome. Kufuneka kuthathelwe ingqalelo ukuba iiseli ezinee-chromosomes ezininzi okanye ii-chromosomes ezingonelanga azisebenzi kakuhle. Abanye abakwazi ukusinda okanye babangele umhlaza. Le yingxaki yezifo ezithile zemfuza. Xa iiseli zifumana i-mitosis Abahluleli i-DNA yabo ngokungacwangciswanga kodwa bayilahla ngeemfumba. Ngokuchasene nokwenzekayo kwi-DNA, bahambisa ii-chromosomes eziphindiweyo kuthotho lwamanyathelo alumkileyo.
Izigaba ze-mitosis
Makhe sibone ukuba zeziphi izigaba eziphambili ze-mitosis kwaye zibaluleke kangakanani. Amanqanaba zii-4 ezisisiseko: iProphase, iMetaphase, iAnaphase kunye neTelophase. Kwezinye iincwadi zezifundo mhlawumbi ubonile ukuba kukho isigaba sesihlanu. Nangona kunjalo, ezi-4 zithiwe zezona zibalulekileyo. Zonke ezi zigaba zinokulandelelana ngokungqongqo ngokulandelelana. Kufuneka kugcinwe engqondweni ukuba i-cytokinesis nayo iyenzeka ngexesha le-mitosis. Le yinkqubo enoxanduva lokwahlula umxholo onayo iseli ukwenza iiseli ezimbini ezintsha. Le nkqubo ye-cytokinesis iqala nge-anaphase okanye i-telophase.
Ukwazisa kwangoko
Apha i-mitotic spindle iqala ukwenza. Ii-chromosomes nazo ziqala ukudibanisa kwaye i-nucleolus yeseli iyanyamalala. Kweli nqanaba le-mitosis, iseli laqala ukophula ezinye izakhiwo zeseli yesinti ukuze yakhe ezinye. Ngale ndlela kunokwenzeka ukulungiselela inqanaba elifanelekileyo ukuze ii-chromosomes zahlule. Njengoko ii-chromosomes zixinana, zinokwahlula kwaye zahlule ngokulula kamva. I-mitotic spindle iqala ukwenza. Ayisiyonto ingaphezulu kwesakhiwo esenziwe ngee-microtubules. Ezi yimicu eyomeleleyo eyinxalenye yento eba ngamathambo eseli. Owona msebenzi uphambili we-mitotic spindle kukulungiselela zonke ii-chromosomes kwaye uzihambise kwindawo yazo ngexesha le-mitosis. Esi sibophelelo sikhula phakathi kwee-centrosomes njengoko zohlukana.
I-nucleolus yeseli yinxalenye ye-nucleus apho kwenziwa khona i-ribosomes. Lo mmandla wonke uyanyamalala xa kuqala i-mitosis. Inyani yokuba i-nucleolus iqala ukunyamalala yenye yeempawu zokuba i-nucleus iqale ukubola.
Ukwazisa emva kwexesha
Apha kufunwa ukuba imvulophu ye-nucleus ibole kwaye ii-chromosomes ziqala ukubala ngokupheleleyo. Okwangoku ii-chromosomes zidibene ngakumbi kwaye imvulophu ye-nucleus iqala ukophuka ukuze ikhokele ii-chromosomes. I-mitotic spindle ikhula ngokukhawuleza kwaye ngokukhawuleza kwaye ezinye ii-microtubules zithatha ii-chromosomes. Ezi microtubules zinokudityaniswa kwii-chromosomes kwi-kinetochore. I-kinetochore licandelo eliqulathe iiproteni ezikwi-centromere yodade ngamnye chromatid.. Kwelinye icala, ii-microtubules ezingaphumeleliyo ukubopha kwi-kinetochore zincamathele kwii-microtubules kwipali ejongene nayo ukuze kuzinziswe i-spindle.
Imetaphase
I-metaphase yinxalenye ye-mitosis apho ii-chromosomes sele zilawula ukuzilungelelanisa kunye nomnye kwipleyiti yemetaphase. Apha ziphantsi koxinzelelo olusuka kwi-spindle ye-mitotic. Ii-chromatids zodade ezimbini ze-chromosome nganye zithathwa zezi microtubules kwiipali ezichaseneyo. Kule metaphase, into yokuluka inoxanduva lokufaka zonke ii-chromosomes ezihamba kunye.
Ngaphambi kokudlulela kwinqanaba elilandelayo, iiseli zijonga ukuba zonke ii-chromosomes zikwi-metaphase plate kunye ne-kinetochores yazo eqhotyoshelwe ngokuchanekileyo kwii-microtubules. Kulapho oku kukhangelwa khona okuqinisekisa ukuba yonke into ihamba ngokuchanekileyo. Ukuba i-chromosome ayilungelelananga ngokuchanekileyo, iseli iyema ukwahlula de le ngxaki isonjululwe.
Isigaba seMitosis: Anaphase
Kweli nqanaba ii-chromatids zahlukile enye kwenye kwaye zitsalelwe kwiipali ezichasene neseli. Ii-microtubules esele ziqhotyoshelwe kwii-chromosomes zityhala iipali zokuluka kumacala ahlukeneyo. Kwelinye icala, ii-microtubules ezikwi-kinetochore zitsala ii-chromosomes ezibhekise ezipalini. Indlela yokugcina i-chromatids ngokudibeneyo kukusebenzisa uhlobo oluthile lweglue protein. Lo mmiselo wenziwe ziiproteni kwaye ngexesha le-anaphase ekugqibeleni liyonyamalala ukuvumela ii-chromatids ukuba zahlukane. Ngoku nganye ine-chromosome yayo. Ii-chromosomes kwisibini ngasinye zitsaliwe kwiziphelo ezichaseneyo zeseli. Ii-microtubules ezingafakwanga kwii-chromosomes zide ukuze zikwazi ukutyhala kunye nokwahlula iipali, zisenze ukuba iseli lide.
Zonke ezi nkqubo ziqhutywa ziiprotein zeemoto. Ngoomatshini beemolekyuli abanokuhamba ngeesekethe zemicrotubule.
I-Telophase
Lelona nqanaba lokugqibela le-mitosis kwaye apha i-spindle iyanyamalala kwaye inwebu yenyukliya inokubumba ijikeleze iqela ngalinye lama-chromosomes. IiChromosomes zihlala zithambekele kwaye ezimbini zeentombi ziya kuba sele zisazi ukuba zenziwe.
Ndiyathemba ukuba ngolu lwazi unokufunda ngakumbi malunga nenkqubo ye-mitosis.