Uyini ezimbili hybrid crossover

Imithetho yefa Mendel ngoba monohybrid engu- walondoloza esimweni eziyinkimbinkimbi ezimbili hybrid. Kulesi hlobo amafomu umzali nokuxhumana kuhluke ngu amabili namabhuzu izici okungafani.

Cabanga ngesibonelo sika-Mendel dihybrid esiphambanweni isiqinisekiso imithetho. Awela ezimbili izinhlobonhlobo uphizi: izimbali ezimhlophe kanye usebe evamile futhi izimbali purple futhi usebe side. Bonke laba bantu-lokuqala sizukulwane izimbali evamile nomhlophe kanye phehla. Kule siphethe ngokuthi umbala omhlophe (okhonjiswe C) nobude evamile (ukubhala E) - kuyinto okuyizona izici umbala onsomi (s) kanye phehla elongate (e) - esikhubazayo. Lapho i-self-impova isizukulwane sokuqala izitshalo kuhlukaniswa. Ngenxa ukucaciseleka yakha icebo ukuwela.

cross Okokuqala: P1 x CCEE CCEE

G 2Ss futhi 2Ee

F1 CCEE

I kokuzalela yesibili (selfing F1 nzalo) P2 x CCEE CCEE. cross Dihybrid uya ukwakha 16 izinhlobo zygotes. gamete ngamunye sizoqukatha omele omunye kusukela isakhi sofuzo ngazimbili nge P-E-E ngazimbili. Lapho yilesi sakhi C okungenzeka alinganayo kungenziwa kuhlangene E noma e yena, futhi kungaba ukuhlanganisa nge E noma nge kwaphumela hybrid CCEE ngamafomu imvamisa alinganayo gamete izinhlobo 4: .. CE, Gen, Ce, ce. Obedin ndawonye, akha eziphilayo ezifana: 9 nge Corolla evamile ezimhlophe, siphethe 3 ezimhlophe elongate phehla 3 nge usebe imajenta evamile futhi imajenta 1 nge-abarimi side.

Esizukulwaneni yesibili bewela nzalo ngaphandle, amafomu nibonakala efanayo sabazali, bobunjwa akhiwa ne inhlanganisela entsha izinhlamvu (combinative noma kokuhlukana zofuzo). Lesi simo esiyingqayizivele sibangelwa linendima ebalulekile ukuvela ezithela inhlanganisela ezintsha zezici oluhambelana. Futhi ngenkuthalo lisetshenziswe zizalela, lapho crossbreeding zezitshalo nezilwane izinhlobo okuthuthukisiwe izinhlobo kwenza kube nokwenzeka ukwethula izinhlobo ezintsha zezinto eziphilayo.

Isibalo phenotypes e F2 lingaphansi kuka inani genotypes. Lokhu kungenxa yokuthi inyunyana gametes ezahlukene anganika okufanayo izici morphological. Ngakho, sithola wokuqhekeka phenotype - 9: 3: 3: 1.

Lezi zihloko ezimbili hybrid crossover kungenzeka uma izakhi zofuzo evelele asezindaweni Ama-chromosomes e nonhomologous. isisekelo Cytological yokuhlangana enjalo uphinde - meiosis kanye kokukhulelwa. Mendel ngaphawula ukuthi abaningi kangaka nokuxhumana zezakhi zofuzo pair of izimfanelo ngamunye ngofuzo ngokwahlukana yilowo nalowo ngendlela, ngokukhululekile kokuba ezihlanganiswe zonke inhlanganisela kunokwenzeka (ifa ezimele).

Zonke amaphethini ifa ukuthi Mendel isethelwe olulodwa futhi ezimbili hybrid kokuzalela, nobuntu inhlanganisela eziyinkimbinkimbi. Ngakho, poligibridnoe Ukunqamula kwenzeka uma eziphilayo zithathwa salokhu ovelele izici ezintathu noma ephikisanayo ngaphezulu. At inhliziyo lokuhlanganisa kwabo gametes kanye ukuhanjiswa ukwaziswa kwezakhi zofuzo kukhona imithetho ukugaya kanye ezimele ifa.

Kulokhu osekushiwo, siphetha ngokuthi ezimbili hybrid crossover - is, eqinisweni, ezimbili ngokuzimela efinyelela Ukunqamula abavamile, lapho omunye uphawu alternative kunakwe (monohybrid). Lokhu kuyiqiniso kakhulu ezimileni nasezilwaneni.