Ulwahlulo lweselula

ISahlulo asiyiyo nje isibambiso sokubuyisa ubuqotho beethambo, kodwa kwakhona ukuveliswa kwezinto eziphilayo. Ngokwalo, ukwahlukana kweeseli kubandakanya ukubunjwa kwamabini amabini okanye ngaphezulu kwimizali evela kumzali omnye. Ama-Chromosomes ahlala kwindawo ebaluleke kakhulu kwinkqubo yesahlulo seseli. Banoxanduva lokudluliswa kolwazi phakathi kwezizukulwana.

Ulwahlulo lweselula. I-Mitosis kunye ne-meiosis

Kukho iintlobo ezimbini ezibalulekileyo zokuhlukana - mitosis kunye ne-meiosis. Eyokuqala ibonisa ukubunjwa kweeseli ezimbini zeentombi ezivela kwiseli yomzali omnye. Inani lama-chromosomes kwezo zombini iiseli zihlala zifana neseli lomzali, oko kukuthi, iiseli zifanayo. Ukwanda kwenani lama-chromosomes kwenzeka ngaphambi kokuhlukana. Ngaloo ndlela, iseli ivela kwi-diploid ibe yi-tetraploid. Ekugqibeleni iiseli ze-diploid zenziwe.

I-Meiosis yenziwe ngamaseli amane. Ngexesha elifanayo, ngamnye kubo unama-chromosomes isiqingatha se-chromosomes yomama. I-Meiosis idla ngokukhawuleza emva kwecandelo lokuqala. Ngenxa yoko, enye idilogidi ivelisa ezine ze-haploid.

Phakathi kwamacandelo iseli kufuneka ikhule kwaye iphuhlise, ilungiselele ukwahlula. Ngeli xesha, amaninzi amaprotheni aqokelela kuyo kwaye, ngaphezu koko, i-organoids ebaluleke kakhulu iphindwe kabini, kwaye kunye nabo ngama-chromosomes.

Kuyinto yesiko ukuhlukanisa izigaba ezine ze-mitosis, ezithatha indawo enye ize zigcine iiyure ezimbini. Ulwahlulo lweMitotic lweseli luquka ezi zilandelayo.

Kwisigaba sokuqala i-centrioles ihambela kwizibonda zeseli. Emva koko, i-fission e-spind isakhiwe. Iipromosomes ziba zibalaseleyo. Ngelo xesha, imvulophu yenyukliya iyachitheka, kwaye i-nucleolus iyalala.

Isigaba sesibini sokwahlukana kukuba i-chromosomes kufuneka ifumaneke kunye ne-equator yeselityu kwaye ifakelele kwi-fission spindles.

Kwinqanaba lesithathu, i-chromosomes yentombi okanye i-chromatids iqalisa inkqubo yokungafani kwizibonda zeeseli ngenxa yeengcingo.

Kwinqanaba elilandelayo, i-fission spindles iyanyamalala, iigobolkliya zenyukliya ziqala ukuzungeze i-chromosomes esele ihlakazekile. Emva koko, i-cytoplasm kunye neentombi zeentombi zahlula. Yile ndlela iseli ehlula ngayo.

Meiosis

I-Meiosis isoloko ihlanganiswa nokuveliswa ngokwesini kwezisele , kunye nokwakhiwa kweeseli zegciwane kwi-fungi, izityalo kunye nezilwanyana. Ulwahlulo lwamaseli luqukethe iinkqubo ezimbini zokulandelelana, kodwa i-chromosome kabini iyenzeka kuphela ngaphambi kwecandelo lokuqala. Yingakho iiseli ziqulethe isiqingatha sesethi yama-chromosomes. Inkqubo ye-meiosis iqulethe izigaba ezibini eziphambili - phambi kohlulo naphambi kohlulo, ngasinye sichazwe ngamaqela ahlukeneyo.

Kwinqanaba lokuqala phambi kwesahlulo, i-chromosomes ibonakala ngokucacileyo. Kule meko, i-chromosomes ye-homologous iqala ukwenza iimbini, zidibanise kunye, zize zijikelele ubude bayo. Emva koko, imimandla yee-homologous zengingqi ze-chromosomes zitshintshana phakathi kwazo kwaye zihluke. Ukongezelela, i- chromosomes ye-homologous kufuneka idibene kunye ne-equator. Kwinqanaba elilandelayo, i-chromosomes, equkethe ii-chromatids ezimbini, iqala ukudibanisa kwizibonda. Kule meko, ukuhlukana kwendidi nganye akuxhomekeke ekuhambeni kweminye mibini ye-chromosomes. Ngaloo ndlela, iiseli zeentombi zenziwe ngekhefu ye-chromosome.

Icandelo lesibini leseli. Isigaba sokuqala siquka ukutshatyalaliswa kwemvulophu yenyukliya kunye nokunyamalala kwe-nucleolus. Emva koko, i-spindle yecandelo ibonakala. Emva koko ama-chromosomes kufuneka adibanise kunye ne-equator, afake iintambo. Kwinqanaba lesithathu, i-chromatids yeentombi zeentombi zihamba kancane kwiibonda. Emva koko, iiseli ezinee-chromosomes zivela. Emva koko, iiseli zesini zenziwa kubo. Emva kokuhlanganiswa kweeseli zesini, inani lama-chromosomes kwiseli elitsha libuyiselwa.