Umsebenzi Reproductive nokubaluleka yezinto eziphilayo meiosis

Umsebenzi okuzala omzimba lwenziwa ngexesha loxhulumaniso lwe gametes ezimbini (iiseli intsholongwane) xa siganeko kunye nophuhliso elandelayo umzimba sokuncedisa elilodwa - iqanda. Xa iiseli zesini abazali kufuneka ezithile n-zofuzo. Wabiza haploid. Elilodwa ithatha iseti kwezi, oko iseli diploid, ie, inombolo chromosome 2n apho: lukamama enye yooyise omnye. Eziphilayo meiotic division ukubaluleka olulodwa kwiseli sikuko yokuba Bulelani kuyo, iseli haploid wabumba kwiiseli diploid.

definition

Meiosis eziphilayo kuthiwa uhlobo mitosis; ngenxa yayo diploid iiseli somatic ye amadlala esini zahlulwe gametes 1n. Xa kernel aqhamileyo, kukho ngxubevange gametes. Ngoko ke, oko isazama 2n chromosome elimisiweyo. Intsingiselo meiosis kukuqinisekisa ekulondolozweni sibubona uhlobo ngalunye eziphilayo zofuzo kunye nobungakanani ezifanelekileyo DNA.

incazelo

Meiosis - le nkqubo eqhubekayo. Le nkqubo ibandakanya iintlobo ezimbini yokwahlula ngokulandelelana zilandelayo omnye komnye: meiosis mna meiosis II. Nganye yeenkqubo, ke, iqulathe prophase, metaphase, anaphase, telophase. Icandelo lokuqala meiosis okanye meiosis mna, yenza inani zofuzo, ngamanye kukho lo mkhuba kwicandelo zokunciphisa ekuthiwa njalo-. Xa ke Inqanaba lesibini meiosis okanye meiosis II, iiseli haploid akuthethi asongele utshintsho, igcinwa khona. Le nkqubo ibizwa ngokuba ukwahlula equational.

Zonke iiseli kwi nqanaba meiosis, athwale ezinye iinkcukacha kwinqanaba yemfuza.

• prophase Meiotic wokuqala - Inqanaba okuqhubekayo chromatin kweleli kwaye ukuyilwa zofuzo. Ekupheleni kwesi senzo entsonkothileyo kakhulu genetic material langoku kwimo yalo yantlandlolo - 2n2 zofuzo.
• Metaphase uyeza - ifike inqanaba ubuninzi Helix. Le zofuzo nangoku ayikatshintshi.
• Anaphase of meiosis sikhatshwa unciphiso. isibini ngasinye zofuzo yabazali waseza noko amnye zaso intombi. genetic material itshintswa kumafa, njengoko Inombolo chromosome waba isiqingatha: ngokuba kwipali nganye iseli kuyimfuneko ukuba 1n2 chromosome.
• Telophase - isigaba xa uyila undoqo, wahlukana kukho icytoplasm. zidalwe iiseli Ntombi yam, zibe-2 yaye ngamnye chromatids ezimbini. ie ibekwe zofuzo kwi haploid kuzo.
• interkinesis Further waphawula, ikhefu elifutshane phakathi isigaba sokuqala nesesibini meiosis. Iiseli ezimbini Intombi bakulungele ukungena Inqanaba lesibini meiosis, olwenzeka yi indlela efanayo naleyo mitosis.

Ukubaluleka yezinto eziphilayo meiosis ke ngoko kule yokuba inyathelo wayo wesibini iindlela ezintsonkothileyo sele kwasekwa iiseli haploid 4 - 1n1 zofuzo. Oko kukuthi, iseli enye unina diploid onika ubomi ezine - ngamnye chromosome haploid iseti. Kwenye isigaba sokuqala meiotic isidanga genetic material recombines, kwaye inyathelo lesibini yenziwa intshukumo zofuzo kunye chromatids kwiipali ezahlukeneyo kwiseli. Ezi iintshukumo - umthombo ukwahluka kunye nendibaniselwano ezahlukeneyo intraspecific.

iziphumo

Ngenxa yoko, ukubaluleka ngokobugcisa meiosis, ngokwenene olukhulu. Okokuqala, kufanele kuqatshelwe njengoko eziyintloko, iqonga engundoqo nesisekelo gametes. Meiosis kuqinisekiswa ukudluliselwa kolwazi yemfuza zenye ephilayo komnye, ngokuxhomekeka ukuba zizala ngayo. Meiosis yenza iindibaniso intraspecific zenzeka ngenxa iiseli intombi kwahluka kungekuphela evela kubazali kodwa zihlukile.

Ukongeza, intsingiselo yezinto eziphilayo meiosis iqulathe ekunikeni ekunciphiseni inani zofuzo lo mzuzu xa akhiwa iiseli lwegciwane. Meiosis uqinisekisa haploid zabo; ngexesha aqhamise ngesakhiwo elilodwa chromosome diploid luyagcinwa kwakhona.