Njani na ngokucandeka yenyukliya? ngokucandeka Types

Zonke iseli kuqala ebomini balo xa ababezahlule evela kumzali, yaye ekugqibeleni ukuba, enika ithuba kuvela kwiiseli zabo intombi. Nature enikiweyo ngaphezu kwesinye indlela yokwahlula undoqo, ngokuxhomekeke kwisakhiwo sabo.

Iindlela yokwahlukana cell

Lidala undoqo ixhomekeka kuhlobo cell :

- ngokucandeka lokubini (ifumaneka prokaryotes).

- amitosis (division ngendlela ethe ngqo).

- Mitosis (eziqhelekileyo eukaryotes).

- Meiosis (uqhekeko iiseli intsholongwane).

Iintlobo ngokucandeka zigqitywa uhlobo kwaye ziyangqinelana isakhiwo iseli kwaye umsebenzi ngayo ekusebenzeni macroorganism okanye ngokwayo.

ngokucandeka binary

Amaninzi olu hlobo ifumaneka kwiiseli prokaryotic. It sikuko kabini i setyhula DNA. ngokucandeka Binary le ngumongo ke ngoko ngokuba ngenxa iseli unina kukho intombi ezimbini ubungakanani ngokulinganayo.

Emva umba yemfuza (DNA okanye RNA molecule) ilungiselelwe ngokufanelekileyo, ngamanye amazwi oko kabini, othabathela eludongeni kwiseli uqalisa ukwakha ulwahlulo ezinqamlezayo, nto leyo ebegqwese tapered kwaye kukho icytoplasm ihlukane iinxalenye ezimbini malunga ngokulinganayo.

Inkqubo lidala yesibini ekuthiwa lolu okanye ngokucandeka yokubini kolwabelo olungalinganiyo. Kulo mzekelo, iindonga iseli kuvela Buze isahlulo, nto leyo likhula ngokuthe ngcembe. Emva kokuba "izintso," kwaye ubungakanani yeseli unina iya kulingana, ukuba bahlukane. Inxalenye kodonga yeseli ukuba kuhlelwe kwakhona.

amitosis

Eli candelo le ngumongo ezifana nezo ezichazwe ngasentla, kunye umahluko ukuba akukho kabini le impahla yemfuza. Le nqubo echazwe kuqala Remak eziphilayo. Oku kwenzeka xa iiseli pathologically bububumbi (inguqu onobungozi), kwaye norm komzimba ukuze zesibindi izihlunu, intlala kunye inwebu.

Le nkqubo ibizwa yenyukliya ngokucandeka amitosis kuba iseli igcina umsebenzi wayo, kwaye zingabuthisi nabo ngexesha mitosis. Oku kuchaza iimpawu ezingaqhelekanga ezinxulumene inkqubo hlula iseli. Ukongeza, ngqo core ukwahlula udlula ngaphandle yokuluka, ngoko ke chromatin intombi iiseli abelwa ngokufanayo. Koku kulandelayo, iiseli ayide ikwazi ukusebenzisa umjikelo mitotic. Maxa wambi, ngenxa amitosis kwasekwa iiseli multinucleated.

mitosis

Le ngokucandeka enyukliya ngqo. Eyona amaninzi zifumaneka iiseli eukaryotic. Umahluko iphambili yale nkqubo kuxhomekeke kwinto yokuba umntwana kunye iiseli yomama ziqulathe inani elifanayo zofuzo. Ngale umzimba ixhaswa inani elifunekayo iiseli, ngokunjalo neenkqubo ngokutsha kunye nokukhula kunokwenzeka. I mitosis yokuqala iseli isilwanyana esichazwe Flemming.

Inkqubo hlula ngumongo kule meko abazahlulayo ngqo kwi interphase kunye mitosis. Interphase - isimo iiseli kuhlala phakathi kwamacandelo. Oku uyakwazi ukwahlula izigaba ezininzi:

1. ixesha presynthetic - iseli sikhula, oluhlala iiprothini kunye carbohydrate, eli kuhlelwe ATP (adenosine triphosphate).

2. ixesha Synthetic - kabini umbandela yemfuza.

3. ixesha postsynthetic - ukuba kabini izinto zeselula, kukho ziiproteni ezakha edibanise ungumqobo.

Izigaba mitosis

Ulwahlulwa-isiqalo iiseli eukaryotic - inkqubo apho kuyimfuneko ekumiseni organelles ezongezelelweyo - centrosomes. Le ekufuphi ngumongo, kwaye umsebenzi wayo ophambili kukuba ukwenza organelles amatsha - yokuluka. Esi sakhiwo kunceda ukuba babele ngokulinganayo le zofuzo phakathi iiseli intombi.

Kukho izigaba ezine mitosis:

1. Prophase: chromatin kwi ngumongo lushwankathela kwi chromatids, leyo kufutshane centromeres zihamba ngababini ukwenza zofuzo. Nucleoli ukuluhlakaza, ndikuchithachithe ukuya izibonda ezo centrioles iseli. Senziwe othini division.

2. Metaphase: i zofuzo acwangciswe umgca edlula embindini kwiseli ukwenza kwipleyiti metaphase.

3. Anaphase: chromatids diverge ukusuka kwiziko iseli ukuya izibonda, uze emva koko yahlulwe centromere ezimbini. Le intshukumo lunokwenzeka ngenxa entongeni yokuluka candelo, iintsinga apho kuyacuthwa kwaye kusolula zofuzo kumacala ahlukeneyo.

4. Telophase: ukusekwa nuclei intombi. Chromatids kwakhona ijike ibe chromatin, ngumongo ibunjiwe, kwaye kwayo - nucleoli. Igcina lonke icandelo le icytoplasm kunye iseli nodonga Ukwakheka.

endomitosis

Ukunyuka umbandela yemfuza, nto leyo ayiboneleli ulwahlulo ngumongo, ebizwa endomitosis. It ifumaneka kwiiseli izityalo kunye nezilwanyana. Kule meko akukho ngokutshatyalaliswa kukho icytoplasm kunye inwebu isiqalo, kodwa uba chromatin ibe zofuzo, uze emva koko dispiralized.

Le nkqubo ivumela ukufumana ingxenye polyploid apho umxholo iDNA inyuswe. Ezo ndawo stem cell ezifumaneka umongo wethambo. Ukongeza, kukho iimeko, xa kwemolekyuli DNA kabini, kwaye inani zofuzo kuhlala enye. Aziwa njengoku ipholithini, kwaye zifumaneka iiseli yezinambuzane.

mitosis intsingiselo

kwisahlulo Mitotic le ngumongo - yindlela ukugcina iseti rhoqo zofuzo. iiseli Ntombi babe efanayo yemfuza njengomzali yaye zonke iimpawu azalwa kuyo. Mitosis kufuneka ukuba:

- ukukhula kunye nophuhliso eziphilayo multicellular (ukusuka ezo iiseli lwegciwane);

- ukubana ezi zoleko iseli ephantsi kwindawo phezulu nokutshintshwa iiseli igazi (erythrocytes, leukocytes, neeplatelets);

- balungise zomzimba (kwezinye izilwanyana amandla ngenxa yokuzalwa ngokutsha yinto yokuqala efunekayo ukuze ziphile, ezifana ezizinkwenkwezi namacilikishe);

- ukuzala maqanda izityalo kunye nezinye izilwanyana (ezingenamqolo).

meiosis

lidala iiseli lwegciwane Indlela nuclei yahlukile kancinane somatic. Ngenxa yoko, wafumana iiseli ukuba babe isiqingatha yemfuza ababengaphambi zabo. Oku kuyimfuneko ukwenzela ukugcina inani rhoqo zofuzo kwiseli nganye emzimbeni.

Meiosis kwenzeka ngezigaba ezibini:

- isigaba SOKUTHOTYELWA;

- sigaba equational.

Ngendlela eyiyo ngethuba lenkqubo kunokwenzeka kuphela xa iiseli ngesifundo inani zofuzo (diploid, tetraploid, kunye geksaproidnym t. D.). Kakade ke, kuba kuhlala kunokwenzeka ukuba kudlule meiosis neseli iseti engaqhelekanga zofuzo, kodwa ke ukuze zibe nokuphila siyinzala.

Le ndlela iqinisekisa inzalo imitshato interspecific. Ekubeni intsholongwane Iiseli leeseti ezahlukeneyo zofuzo, kube nzima fusion zabo kunye nenkangeleko yenzala akhulayo kwaye otyebileyo.

Icandelo lokuqala meiosis

isigaba uphinda igama abo mitosis: prophase, metaphase, anaphase, telophase. Kodwa kukho ezinye umahluko omkhulu.

1. Prophase: iseti kabini zofuzo kwenza uthotho utshintshwano, edlula kwizigaba ezintlanu (leptotena, zygotes, noPaquita, diplotene, diakinesis). Kukho konke oku enkosi conjugation nokuwela-over.

Conjugation - le ukuhlangabezana zofuzo homologous. Xa leptotene therebetween ukwenza zixhobo angamarhoqorhoqo, koko babe ngababini chromosome zygotene kwaye isiphumo afunyenwe ubume chromatids ezine.

Crossover - inkqubo lomnqamlezo-amacandelo ngokutshintshiselana phakathi chromatids udade okanye zofuzo homologous. Oku kwenzeka ekuqaleni komdlalo pachytene okwangoku. yodibano senziwe (chiasm) zofuzo. Xa abantu, yokutshintshiselana inokuba phakathi ezingamashumi amathathu anesihlanu ukuya emashumi mathandathu anamithandathu. Isiphumo sale nkqubo ke ukungafani genetic onesiphumo eziphathekayo, okanye Ukwahluka gametes.

Xa kuza diplotene isigaba chromatids ezine izakhiwo luyatshatyalaliswa ize udade zofuzo vzaimoottalkivayutsya. Diakinesis igqibe inguqu ukusuka prophase ukuya metaphase.

2. Metaphase: zofuzo aqondwe kufutshane ikhweyitha esiseleni.

3. Anaphase: zofuzo, sekunjalo ezibandakanya chromatids ezimbini diverge nezibonda esiseleni.

4. Telophase: hlula yokuluka ibhuqiwe, kubangela uluhlu ababini iiseli kunye iseti haploid zofuzo yokuba kabini kunaleyo DNA.

Icandelo lesibini meiotic

Le nkqubo kwakhona ngokuba "mitosis, meiosis." Xa mzuzu phakathi izigaba ezibini DNA phindwa ayenzeki, kwaye iseli yesibini ongena prophase iseti efanayo zofuzo, apho wahlala emva 1 telophase.

1. Prophase: zofuzo ngamafuphi abapasileyo iziko iseli yokuzahlula (iintsalela bayo buyahluka izibonda yeseli), kwaye esingxotyeni siyabutyaka isiqalo wambumba division edibanise elahliweyo nkqo entongeni yokuluka besigaba sokuqala.

2. Metaphase: zofuzo zikwindawo kwi-ikhweyitha, usenziwa metaphase nembasa.

3. Anaphase: zofuzo zahlulwe chromatids ukuba angakanani kuwo onke amacala.

4. Telophase: chromatids e iiseli intombi benziwa core dispiralized zibe chromatin.

Ekupheleni kwesigaba sesibini kwiseli umzali, asinaso nkampani ezine ezinesiqingatha iseti zofuzo. Ukuba meiosis kwenzeka kubanjiswene ne kumgca intsholongwane (oko kukuthi, ukuyilwa iiseli sex), ukwahlulwa zibe kakhulu obungalinganiyo, kwaye ezenziwa kwiseli enye iseti haploid zofuzo nokucuthwa ezintathu ithole, hayi bethwele iinkcukacha yemfuza kuyimfuneko. Iyimfuneko ukuze kuqinisekiswe ukuba iqanda amadlozi wahlala kuphela isiqingatha zofuzo yeseli lomzali. Ngapha koko, le fomu yokwahlukana inyukliya ibonelela imbonakalo zizifundo ezintsha yemfuza, kwakunye ilifa olunyulu alleles.

Xa inguqulelo elula meiosis ukho xa kukho ibha enye kuphela kwisigaba sokuqala, kwaye eyesibini kukho crossover. Izazinzulu zibonisa ukuba le fomu siphu- yendaleko of meiosis eqhelekileyo eziphilayo multicellular. Mhlawumbi zikho nezinye iindlela ngokucandeka enyukliya, izazinzulu musa kakazi.