Ukuphindaphindeka - ukuphinda-: iseli ukusuka kwiseli

Ukuphinda ukuyilwa iikopi ezimbini ezifanayo - zesiganeko kakhulu eqhelekileyo kwiinkqubo eziphilayo. Amaxesha amaninzi le kabili kuthiwa ukuphindaphindeka. Le yokugqibela kunokwenzeka kumanqanaba ahlukeneyo lombutho lomba - ngqo DNA zofuzo kunye neeseli yonke. Ngelo xesha, ukuba inkqubo wahamba kakuhle, wafumana iiyunithi ezimbini twatse. Ukuphindaphindeka - ukuphinda-le izacholo yangoku.

Indlela kanye ndawo

I umdla kakhulu ubuvuvu zonke ezinye iintlobo kuthathwa DNA ukuphindaphindeka. Le yinkqubo ethatha indawo ngaphezu zigaba eziliqela, iyileyo ukuchana kubalulekile, kuba inaccuracy kuxhokonxa Yindibanisela protein ngokungafanelekanga kakhulu ukuba angakulungeli ukusetyenziswa kwi iseli kwaye nenyama xa iyonke.

Loqalo lwencopho

Ukuphindaphindeka luqala iseli kabini DNA, leyo iziphumo ukuliphinda zofuzo. Kodwa ukuphindaphindeka - yintsika yonke inkqubo. It iqulathe izigaba ezithathu: okokuqala, amalinge, okwesibini, zobude, yaye okwesithathu, ukupheliswa. Umsebenzi luqala enzyme iingongoma ezibalulekileyo - replicators kunye nabo kuphela. Ekuqaleni kwindawo ephosakeleyo lunokuyitshintsha yonke inkqubo. I-enzayim ye-kuvala isebenze iiproteni ezithile eyenza ezintsonkothileyo pre-phindana efunekayo DNA buya. Phambi kokuba uphinda-phindo lwe-DNA isikwe ngamalungu amabini enqanda ezithile.

Le chain iyavumelana

Xa zobude kwi isizalo kwakhiwa chain umzali ezisebenzisanayo. Oko kukuthi, umntu lowo ke zenze molecule epheleleyo. Inkqubo kukho ukupheliswa ukuba nayo yenzeka endaweni ethile. Kukho iyunithi okukhethekile - replicon. Le isiqwenga DNA eyakha ekuhambeni kwexesha. DNA ukuphindaphindeka - isiseko, ngaphandle lithe lwenziwe zofuzo. Le yokugqibela lwenzeka xa iseli ulungiselela ukuba bazohlule.

Protein njengophawu

Iqala chromosome kabini kwisithuba kwiiyure ezimbalwa emva kokuba kwenzeke DNA buya. Ukuze kuvuselelwe chromosome, kufuneka iiseti kuphela entsha ye deoxyribonucleic acid, kodwa iiproteni eziyinxalenye izixhobo chromosome, kunye kuyondelelaniswe zabo kufuna ixesha. Fast ukuphindaphindeka - umqondiso lomhlaza. Ukuba ibona iproteni kakhulu, uphawu olukhulu candelo yeseli, ugqirha uqala ukuba alamu.

indawo eyanele

Kukho inkqubo phindana yinto enkulu - in space kernel ngokwemigaqo Yindibanisela DNA ezintsha ngobulungisa ngokulinganayo, ngoko akukho ubugqwetha, leyo enokukucaphukisa nempembelelo efanayo. Lidla oluninzi amanqaku, ngokuqhelekileyo enesiqingatha ukuya zokuhlola.

Njani kuza kuququzelelwa zofuzo kuxhomekeke eyenzekayo mitosis iseli okanye meiosis. Kwimeko yokuqala, iseli nto yayiza kuba iseti njengesiqhelo, elinesibini - isiqingatha. Ngapha koko, esinye isiqingatha uya iseli ye iqabane yesibini ukuzala ngokwesini. Ukuba meiosis ngequbuliso ukufumana iseti epheleleyo, gamete okanye bangazinzi, okanye ingabe lwaluzibona umntwana egulayo. Noko ke, aba bantwana kusekho bazalwa kaninzi ngaphezu akunjalo, kukho isisu kwi ukukhulelwa kwangethuba, unina ngubani na ukuthatha phezu ovulation ngenyanga okanye ukopha phakathi komjikelo.