I-Monohybridism umqondo kuzakhi zofuzo obhekisela ocwaningweni lwepheya elilodwa lezakhi zofuzo esiphambanweni phakathi kwabantu ngabanye. Kulolu hlobo lwefa, kubhekwa ipheya elilodwa kuphela lama-alleles, okwenza kube lula ukuqonda amaphethini wefa lofuzo.
Kulesi sihloko, sizohlola ukuthi iyini i-monohybridism nokuthi ibonakala kanjani ezinhlobonhlobo zezinto eziphilayo. Sizophinde sethule izivivinyo ezixazululiwe ukuze sikusize uhlanganise okuqukethwe futhi usebenzise imiqondo okuxoxwe ngayo ekusebenzeni. Ngalezi zibonelo, uzoqonda kangcono ukuthi izici zofuzo zidluliselwa kanjani kusuka kwesinye isizukulwane kuya kwesinye nokuthi izakhi zofuzo zisakazwa kanjani ngesikhathi sokuzalana.
Qonda umqondo we-monohybridism ngesibonelo esisebenzayo.
I-Monohybridism ingumqondo obalulekile kuzakhi zofuzo obhekisela ekuhlaziyweni kwepheya elilodwa lezakhi zofuzo esiphambanweni phakathi kwabantu ngabanye. Kulolu hlobo lwesiphambano, sibona ukuhlukaniswa kwesici sofuzo esisodwa kuphela.
Isibonelo esisebenzayo sokuqonda i-monohybridism isiphambano phakathi kwezitshalo zikaphizi ezinembewu eyindilinga (ebusayo, emelwe ngu-L) nezitshalo ezinembewu eshwabene (i-recessive, emelelwa ngu-l). Ngokuwela isitshalo se-heterozygous (Ll) nesitshalo se-homozygous recessive (ll), singabona ukuthi ama-alleles ahlukanisa kanjani enzalweni.
Esiphambanweni esishiwo ngenhla, amathuba okuthola inzalo enembewu eyindilinga (i-genotype LL noma i-Ll) angama-50%, kanti amathuba okuthola inzalo enembewu eshwabene (i-genotype ll) nawo angama-50%. Lokhu kwenzeka ngenxa yesimiso sokuhlukaniswa kwe-allele ngesikhathi sokubunjwa kwe-gamete.
Ngakho-ke, i-monohybridism isivumela ukuba siqonde ukuthi i-pair of genes iziphatha kanjani esiphambanweni nokuthi ama-alleles adluliselwa kanjani enzalweni, ngokulandela imithetho yezakhi zofuzo ezakhiwe nguMendel.
Ukuqonda umqondo wokuwela i-Monohybrid kanye nokubaluleka kwayo kuzakhi zofuzo.
I-Monohybridism ingumqondo oyisisekelo kuzakhi zofuzo obhekisela ocwaningweni lweziphambano phakathi kwabantu abahluke ngepheya elilodwa kuphela lezakhi zofuzo. Kulolu hlobo lwesiphambano, abantu bangama-homozygous kwenye isakhi sofuzo kanye ne-heterozygous kwenye. Lokhu kusivumela ukuthi sihlaziye ifa lesici esisodwa emphakathini othile.
Iziphambano ze-Monohybrid zibalulekile kuzakhi zofuzo ngoba zisivumela ukuba siqonde ukuhlukaniswa kwama-alleles kanye nokudluliselwa kwezakhi zofuzo kusuka kwesinye isizukulwane kuya kwesinye. Ngalolu hlobo lwesiphambano, kungenzeka ukuhlaziya ubudlelwano phakathi kwezakhi zofuzo kanye nemiphumela yazo ye-phenotypic, kube nesandla ekuthuthukisweni kolwazi mayelana nofuzo nokuhlukahluka kofuzo.
Ukufanekisa i-monohybridity, singacabangela isiphambano phakathi kwezitshalo ze-pea ezihlukile ngombala wembewu. Ake sithi isitshalo se-homozygous green-seeded (VV) siwela ngesitshalo esinembewu ephuzi e-homozygous (vv). Umphumela walesi siphambano uzoba isizukulwane se-heterozygous F1 (Vv), lapho bonke abantu bezoba nembewu eluhlaza ngenxa yokubusa kwe-V allele phezu kwe-v allele.
Ukunquma ingxenye ye-genotypic ne-phenotypic yesizukulwane se-F2 salesi siphambano, singasebenzisa isikwele se-Punnett. Uma kubhekwa ukuthi abantu be-F1 bayi-heterozygous (Vv), sizoba nokusabalalisa kwe-genotypic okulandelayo: 1/4 homozygous dominant genotype (VV), 1/2 heterozygous genotype (Vv), kanye ne-1/4 homozygous genotype (vv). Mayelana ne-phenotype, sizoba nokusatshalaliswa okulandelayo: 3/4 imbewu eluhlaza kanye nembewu eyi-1/4 ephuzi.
Ngakho-ke, ucwaningo lwe-monohybridism ngokusebenzisa iziphambano ze-monohybrid lubalulekile ekuqondeni ifa lesici esisodwa nokuhlaziya ukudluliswa kwezakhi zofuzo kusuka kwesinye isizukulwane kuya kwesinye. Ngalolu hlobo lwesiphambano, kungenzeka kuphenywe ubudlelwano phakathi kwezakhi zofuzo nama-phenotypes, okunomthelela ekuthuthukisweni kofuzo kanye nesayensi yezinto eziphilayo iyonke.
I-F1 ne-F2 kuzakhi zofuzo: ukuqonda izizukulwane kanye nefa lezici zofuzo.
Ocwaningweni lwezakhi zofuzo, kubalulekile ukuqonda incazelo ye-F1 ne-F2, emele izizukulwane ezihlukene ekuhlolweni kokuzalanisa. Isifinyezo esithi F1 sibhekisela esizukulwaneni sokuqala senganekwane, esiphuma esiphambanweni phakathi kwezidalwa ezimbili zabazali. Ngokulandelayo, isifinyezo esithi F2 sibhekisela esizukulwaneni sesibili se-filial, esitholakala ekuhlanganiseni kwabantu abavela esizukulwaneni se-F1.
Uma kukhulunywa ngefa lezici zofuzo, i-monohybridism ingumqondo obalulekile. Kuhilela ukudluliselwa kwepheya elilodwa lezakhi zofuzo kusuka kwesinye isizukulwane kuya kwesinye. Kulolu hlobo lwesiphambano, izinto eziphilayo ezihilelekile ziyehluka kupheya eyodwa kuphela yama-allele ngesici esithile.
Ukuze uqonde kangcono i-monohybridism, ukuzivocavoca okusebenzayo kungenziwa. Isibonelo, ngokuwela izitshalo ze-pea eziyi-heterozygous yombala wembewu (Aa), kungenzeka ukubikezela isilinganiso se-genotypic ne-phenotypic yenzalo esizukulwaneni se-F2. Ngokwemithetho kaMendel, ama-25% enzalo kulindeleke ukuba abe yi-homozygous dominant (AA), 50% heterozygous (Aa), kanye nama-25% we-homozygous recessive (aa).
I-Monohybridism: Qonda ifa lofuzo olulodwa kufuzo lomuntu.
O i-monohybridism umqondo oyisisekelo kuzakhi zofuzo obhekisela efeni lofuzo olulodwa ezintweni eziphilayo. Kulokhu, sikhuluma ngokudluliswa kwepheya elilodwa lama-allele wofuzo oluthile ukusuka kwesinye isizukulwane ukuya kwesinye.
Lapho into ephilayo i-monohybrid, kusho ukuthi inama-allele amabili ahlukene ofuzo oluthile. I-allele iwuhlobo oluthile lwesakhi sofuzo, elinesibopho sokunquma isici esithile somzimba. Isibonelo, isakhi sofuzo esinombala wamehlo singase sibe ne-allele eyodwa yamehlo aluhlaza kanye nesinye samehlo ansundu.
Efa lezakhi zofuzo olulodwa, izakhi zofuzo zilandela imithetho ka-Mendel, echaza ukuhlukaniswa nokusabalalisa ama-allele ngesikhathi sokwakheka kwe-gamete. Ama-Gamete aqukethe i-allele eyodwa kuphela yofuzo ngalunye, oluzohlangana ne-allele yomunye umzali ngesikhathi sokuvundiswa.
Ukuze siqonde kangcono i-monohybridism, singenza izivivinyo ezingokoqobo ezibandakanya ukuhlaziya iziphambano zofuzo. Isibonelo, singabala amathuba okuthi inzalo ithole i-allele ethile kubazali bayo, sicabangela amathuba okuba inhlanganisela yofuzo.
Ngamafuphi, i- i-monohybridism kubalulekile ekuqondeni ukudluliswa kwezimpawu zofuzo kubantu nakwezinye izinto eziphilayo. Ngokutadisha ifa lofuzo olulodwa, singakwazi ukwembula amaphethini ofuzo alawula ukuhlukahluka kwebhayoloji phakathi kwezinhlobo zethu zofuzo.
I-Monohybridism: ukuthi ihlanganisani futhi ixazulule izivivinyo
O i-monohybridism isho ukweqa abantu ababili abahlukene ngesici esisodwa kuphela. Ngokufanayo, lapho siwela abantu bohlobo olufanayo futhi sifunda ngefa lesici esisodwa, sikhuluma nge-monohybridism.
Iziphambano ze-Monohybrid zifuna ukuphenya isisekelo sofuzo sezici ezinqunywa isakhi sofuzo esisodwa. Amaphethini amafa alolu hlobo lokuphambana achazwa nguGregor Mendel (1822-1884), isibalo esivelele emkhakheni wesayensi yezinto eziphilayo futhi owaziwa ngokuthi unguyise wezakhi zofuzo.
Ngokusekelwe emsebenzini wakhe ngezitshalo zikaphizi ( I-Pisum sativum ), uGregor Mendel washo imithetho yakhe eyaziwa kakhulu. Umthetho wokuqala kaMendel uchaza iziphambano ze-monohybrid.
Ihlanganisani?
Njengoba kushiwo ngaphambili, iziphambano ze-monohybrid zichazwe emthethweni wokuqala we-Mendel, ochazwe ngezansi:
Umthetho wokuqala kaMendel
Ezidalwa zocansi, kunamapheya e-alleles, noma amapheya ama-homologous chromosomes, ahlukana ngesikhathi sokwakheka kwama-gametes. Igeyimu ngayinye ithola ilungu elilodwa kuphela laleli pheya. Lo mthetho waziwa ngokuthi "umthetho wokuhlukanisa."
Ngamanye amazwi, i-meiosis iqinisekisa ukuthi i-gamete ngayinye iqukethe ngokuqinile ipheya elilodwa lama-alleles (okuhlukile noma izinhlobo ezahlukene zofuzo), futhi kungenzeka ngokufanayo ukuthi i-gamete izoqukatha noma yiluphi uhlobo lwesakhi sofuzo.
UMendel wakwazi ukusho lo mthetho ngokuhlukanisa izitshalo zikaphizi. UMendel walandelela ifa lamapheya ambalwa ezimpawu ezihlukene (izimbali ezinsomi ziqhathaniswa nezimbali ezimhlophe, imbewu eluhlaza ngokumelene nembewu ephuzi, iziqu ezinde ngokumelene neziqu ezimfushane) ezizukulwaneni eziningana.
Kulezi ziphambano, uMendel wayebala inzalo yesizukulwane ngasinye, ethola isilinganiso ngasinye. Umsebenzi kaMendel uveze imiphumela eqinile, njengoba esebenze nenani elikhulu labantu, cishe izinkulungwane ezimbalwa.
Isibonelo, eziphambanweni ze-monohybrid zembewu eyindilinga ebushelelezi enembewu eshwabene, uMendel uthole imbewu eyindilinga ebushelelezi engu-5474 kanye nembewu eshwabene engu-1850.
Ngokufanayo, imbewu ephuzi ewela nembewu eluhlaza ikhiqiza imbewu ephuzi engu-6022 kanye nembewu eluhlaza ka-2001, ngaleyo ndlela isungula iphethini ecacile engu-3:1.
Esinye seziphetho ezibaluleke kakhulu zalolu cwaningo kwakuwukuchaza ukuba khona kwezinhlayiya ezihlukene ezidluliswa kubazali kuya enzalweni. Namuhla, lezi zinhlayiya zefa zibizwa ngokuthi izakhi zofuzo.
Isithombe sika-Punnett
Leli shadi laqala ukusetshenziswa isazi sofuzo u-Reginald Punnett. Kuwukumelwa okuyisithombe kwama-gamete abantu abangabodwana kanye nawo wonke ama-genotype angaba umphumela wezinto ezithakaselekayo. Kuyindlela elula futhi esheshayo yokuxazulula iziphambano.
Izivivinyo ezixazululiwe
Ukuzivocavoca kokuqala
In the fruit fly ( I-Drosophila melanogaster ), umbala womzimba ompunga unamandla (D) ngaphezu kombala womzimba omnyama (d). Uma isazi sezakhi zofuzo sihlukanisa phakathi komuntu oyedwa ophethe i-homozygous (DD) kanye nomuntu o-homozygous recessive (dd), sizoba njani isizukulwane sokuqala sabantu?
phendula
I-homozygous ebusayo ikhiqiza ama-gamete D kuphela, kuyilapho i-homozygous recessive iphinde ikhiqize uhlobo olulodwa lwe-gamete, kodwa esimweni sayo, i-d.
Ngemva kokukhulelwa, wonke ama-zygote akhiwe azoba ne-genotype Dd. Ngokuqondene ne-phenotype, bonke abantu bazoba nomzimba ompunga, njengoba u-D ewufuzo oluvelele futhi uvala ubukhona buka-d ku-zygote.
Sengiphetha, sino-100% wabantu ku-F 1 izoba mpunga.
Ukuzivocavoca kwe-2
Yiziphi izilinganiso eziba umphumela wokuwela isizukulwane sokuqala sezimpukane kusukela kumsebenzi wokuqala?
phendula
Ungazithola kanjani izimpukane F 1 ine-genotype Dd. Bonke abantu ababalwayo bayi-heterozygous yale elementi.
Umuntu ngamunye angakhiqiza ama-gametes D no-d. Kulokhu, umsebenzi ungaxazululwa kusetshenziswa isikwele sePunnett:
Esizukulwaneni sesibili sezimpukane, izici zabazali (izimpukane ezinomzimba omnyama) okubonakala sengathi "zilahlekile" esizukulwaneni sokuqala ziphinde zivele.
Sithole u-25% wezimpukane nge-homozygous dominant genotype (DD), i-phenotype yayo ingumzimba ompunga; I-50% yabantu be-heterozygous (Dd), lapho i-phenotype nayo impunga; kanye namanye ama-25% abantu abane-homozygous recessive (dd), abanomzimba omnyama.
Uma sifuna ukuyibona ngokwezilinganiso, ukuwela kwe-heterozygotes kubangela abantu abampunga abangu-3 kuqhathaniswa no-1 omnyama (3:1).
Ukuzivocavoca kwesithathu
Ezinhlobonhlobo ezithile zesiliva ezishisayo, kungenzeka ukuhlukanisa phakathi kwamaqabunga anamabala namaqabunga abushelelezi (ngaphandle kwamabala, i-monochromatic).
Ake sithi isazi sezitshalo siwela lezi zinhlobonhlobo. Izitshalo eziphuma esiphambanweni sokuqala zazivunyelwe ukuzivundisa ngokwazo. Umphumela wesizukulwane sesibili kwaba yizitshalo ezingama-240 ezinamahlamvu anamabala kanye nezitshalo ezingama-80 ezinamahlamvu abushelelezi. Yayiyini i-phenotype yesizukulwane sokuqala?
phendula
Isihluthulelo sokuxazulula lo msebenzi ukuthatha izinombolo futhi uziguqule zibe izilinganiso, uhlukanise izinombolo ngale ndlela elandelayo: 80/80 = 1 kanye no-240/80 = 3.
Ngokubonakala kwephethini engu-3:1, kulula ukuphetha ngokuthi abantu abadale isizukulwane sesibili babeyi-heterozygous futhi babenamaqabunga anemibala egqamile.
Ukuzivocavoca kwesine
Iqembu lezazi zezinto eziphilayo licwaninga ngombala woboya onogwaja balolu hlobo I-Oryctolagus cuniculus . Ngokusobala, umbala wejazi unqunywa i-locus enama-alleles amabili, A no-a. I-allele inamandla futhi i-A iyaphindaphinda.
Iyiphi i-genotype abantu abaphuma ekuweleni kwe-homozygous recessive (aa) kanye nomuntu onama-heterozygous (Aa)?
phendula
Indlela okumele ilandelwe ukuxazulula le nkinga ukusebenzisa isikwele se-Punnett. Abantu abane-homozygous recessive bakhiqiza ama-gametes kuphela, kuyilapho abantu be-heterozygous bekhiqiza kokubili u-A kanye nama-gametes. Ngokwesithombe, kubonakala kanje:
Ngakho-ke, singaphetha ngokuthi i-50% yabantu izoba yi-heterozygous (Aa) kanti enye i-50% izoba yi-homozygous recessive (aa).
Okuhlukile emthethweni wokuqala
Kunezinhlelo ezithile zofuzo lapho abantu be-heterozygous bengakhiqizi izilinganiso ezilinganayo zama-allele amabili ahlukene kuma-gametes abo, njengoba kubikezelwe izilinganiso ze-Mendelian ezichazwe ngenhla.
Lesi simo saziwa ngokuthi ukuhlanekezelwa kokuhlukaniswa (noma i-meiotic impulse ). Isibonelo salokhu izakhi zofuzo zobugovu, eziphazamisa ukusebenza kwezinye izakhi zofuzo ezifuna ukwandisa ukuvama kwazo. Qaphela ukuthi isici sobugovu singanciphisa ukusebenza kahle kwebhayoloji yomuntu osiphethe.
Ku-heterozygote, isakhi sobugovu sisebenzisana ne-elementi evamile. Okuhlukile kobugovu kungacekela phansi into evamile noma kuyivimbele ukuthi isebenze. Omunye wemiphumela esheshayo ukwephulwa komthetho wokuqala kaMendel.
Izinkomba
- Barrows, E.M. (2000). Ireferensi Yedeski Lokuziphatha Kwezilwane: Isichazamazwi Sokuziphatha Kwezilwane, I-Ecology, kanye Nemvelo . CRC Cindezela
- Elston, R. C., Olson, J. M., & Palmer, L. (2002). I-Biostatistical genetics kanye ne-genetic epidemiology . UJohn Wiley & Amadodana.
- Hedrick, P. (2005). Izakhi zofuzo zabantu . Uhlelo lwesithathu uJones noBartlett Publishers.
- I-Montenegro, R. (2001). I-Human Evolutionary Biology National University of Cordoba.
- U-Subirana, J.C. (1983). I-Genetics Didactics . Izinguqulo zase-Universitat Barcelona.
- Thomas, A. (2015). Sethula iGenetics. Uhlelo Lwesibili Garland Science, Taylor & Francis Group.