Chigawo selo

Kudulidwa si ofunika kubwezeretsa kukhulupirika kwa zimakhala, koma kubalana wa zamoyo. Palokha, selo magawano kumatanthauza mapangidwe maselo awiri kapena kuposa mwana wamkazi ku kholo limodzi. DNA zatenga malo ofunika kwambiri mu ndondomeko ya kugawikana selo. Ndi iwo amene ali ndi udindo kufala kwa mudziwe pakati pa mibadwo.

Cell magawano. Mitosis ndi Meiosis

Pali mitundu iwiri yaikulu ya kugawikana - mitosis ndi meiosis. The choyamba ndi mapangidwe limodzi mwana makolo selo awiri. chiwerengero DNA maselo a awiri akanali yemweyo monga muchipindachi kholo, maselo mwachitsanzo ali ofanana. Kuwonjezera chiwerengero DNA amapezeka pamaso magawano. Choncho, selo kusandulika kwa diploid kuti tetraploid. Kumapeto kwa maselo awiri diploid anapanga.

Meiosis amatchedwa mapangidwe maselo anayi. Pankhaniyi, aliyense DNA izi mu theka poyerekeza kholo la. Meiosis zambiri kukuwonekera mwamsanga gulu loyamba. Chifukwa cha diploid limodzi analandira haploid anayi.

Pakati pa nsoka selo ayenera kukula ndi kukhala, kukonzekera gulu latsopano. Panthawi imeneyi, iwo amasonkhana kwambiri mapulotini komanso kawiri pa organelles zofunika kwambiri, ndipo ndi iwo, ndipo DNA.

Kusiyanitsa anayi mbali ya mitosis, amene atsata mzake ndi kuwonjezera maola awiri. Mitotic magawano selo ikukhudza zotsatirazi.

Mu gawo loyamba kuwonjezera centrioles mizati ya chipindacho. Kenako, mapangidwe spindle. DNA kukhala yoonekera. Pa nthawi yomweyo amasungunula nembanemba nyukiliya, ndi nucleolus kenako kusiyiratu.

Gawo lachiwiri la magawano ndi kuti DNA kukhala pamodzi ndi equator selo ndi angagwirizanitse magawano spindle.

Mu ndime yachitatu mwana DNA kapena chromatids ayambe divergence chifukwa mitengo yonyamulira ya maselo spindles.

Mu sitepe yotsatira kutha spindle, kuzungulira DNA kale omwazika anayamba kupanga envelopu nyukiliya. Pambuyo ukugawa cytoplasm ndi mwana maselo anapanga. Popeza selo magawano amapezeka.

meiosis

Meiosis nthawi zambiri amagwirizana ndi kubereka maselo ndi mapangidwe maselo kugonana bowa, zomera ndi nyama. Chigawo Cell wapangidwa ndi njira ziwiri motsatizana magawano, Koma khromozomu anawaonjezera kuwirikiza kawiri amapezeka kusanachitike gulu loyamba. N'chifukwa chake maselo chifukwa muli nambala theka DNA. The ndondomeko ya meiosis limapangidwa magawo awiri chachikulu - pamaso kugawa n'kuduladula, omwe lagawidwa magawo osiyana.

Mu sitepe poyamba kugawa DNA ndi amamudziwa kuwoneka. Choncho magazi awiri khromozomu anayamba kupanga, mwamphamvu chotsatira mzake, kenako kupotoza mulitali lonse. Kenako, m'madera magazi DNA ndi kusinthana zigawo pakati pa wina ndi mzake anasiyanitsidwa. Komanso magazi DNA ayenera munzere pamodzi dziko. Pa gawo lotsatira DNA, zomwe zigwirizana chromatids awiri anayamba mogwirizana kwa mizati. Kulakwika kwa gulu lirilonse zimadalira wa awiriawiri ena DNA divergence. Choncho anapanga maselo mwana wamkazi ndi chiwerengero theka DNA.

The chachiwiri magawano selo. Chinthu choyamba ndi chiwonongeko cha envelopu nyukiliya ndi kutha kwa nucleoli. Kenako kuoneka spindle. Ndiye, DNA ayenera munzere pa equator ndi kuika pa spindle. Mu gawo lachitatu onse chromatids mwana maselo pang'onopang'ono mogwirizana ndi mizati. Pambuyo kuti pali maselo lokhala umodzi DNA. maselo Komanso nyongolosi anapanga. topangira DNA selo latsopano abwezeretsedwa pambuyo pophatikizana a gametes.