Uas ua tsis tiav dominance - yog tshwm sim ntawm cov kev sis raug zoo ntawm alleles ntawm ib tug noob

Uas ua tsis tiav dominance - ib tug tshwj xeeb kev sis raug zoo noob allele, nyob rau lub weaker recessive kev zoo losis phem tej zaum yuav tsis tau kiag li suppressed hom. Nyob rau hauv raws li txoj cai, qhib Mendel, hom nkaus suppresses kev qhia txog lub recessive. Cov soj ntsuam tshawb nrhiav cov lus hais contrasting zoo nyob rau hauv cov nroj tsuag nrog ib tug manifestation ntawm tog twg los tseem ceeb los yog recessive allele. Nyob rau hauv tej rooj plaub, Mendel ntsib nrog lub tsis ua hauj lwm ntawm cov kev cai, tab sis ho tsis piav lawv.

Ib tug tshiab daim ntawv ntawm qub txeeg qub teg

Tej zaum, raws li ib tug tshwm sim ntawm hla xeeb leej xeeb ntxwv tau txais lub intermediate tej yam tshwm sim, uas tsis tau muab nyob rau hauv lub homozygous daim ntawv ntawm cov niam txiv noob. Uas ua tsis tiav dominance yog tsis nyob rau hauv lub conceptual apparatus ntawm noob caj noob ces mus rau hauv thaum ntxov XX xyoo pua, thaum lawv rediscovered Mendel kev cai. Ces, ntau tej yam ntuj tso zaum nqa tawm kev tshuaj ntsuam genetic thwmsim nrog zaub thiab tsiaj tej khoom (soob, legumes, hamsters, nas, txiv hmab txiv ntoo yoov).

Tom qab cytological kabke nyob rau hauv 1902, Walter Sutton Mendelian qauv ntawm kis tau tus mob tej ntsiab cai thiab kev sis raug zoo nrog cov cim pib piav txoj hauj lwm ntawm tus cwj pwm ntawm cov chromosomes nyob rau hauv lub cell.

Nyob rau hauv tib 1902 Cermak Correns piav rau hauv rooj plaub thaum twg, tom qab hla nroj tsuag nrog dawb thiab liab Corolla nyob rau hauv lub zag paj ntawm liab xim - tsis tiav dominance. Qhov no zaub ntawm lub hybrids (genotype AA) yam ntxwv uas yog intermediate txheeb ze rau homozygous hom (AA) thiab recessive (aa) phenotypes. Ib tug zoo xws li cov nyhuv twb tau piav rau ntau hom ntawm flowering nroj tsuag: snapdragons, hyacinth, zoo nkauj hmo ntuj, txiv pos nphuab.

Uas ua tsis tiav dominance - ib tug yog vim li cas rau cov kev hloov ntawm enzymes ua hauj lwm?

Lub mechanism ntawm cov tsos ntawm ib tug thib peb embodiment ntawm feature yuav tau piav los ntawm txoj hauj lwm ntawm cov kev ua ntawm enzymes uas yog cov nqaijrog los ntawm qhov thiab noob txiav txim seb lub protein qauv. Cov nroj tsuag nrog rau ib tug homozygous hom genotype (AA) enzymes yuav txaus thiab tus nqi ntawm cov xim yuav phim tus nqi rau sib tsuas lub cell kua ntoo.

Homozygotes nrog recessive alleles (aa) xim synthesis tawg whisk tseem uncolored. Nyob rau hauv cov ntaub ntawv ntawm intermediate heterozygous genotype (AA), ib tug tseem ceeb noob tseem muab ib qhov nqi ntawm cov enzyme lub luag hauj lwm rau pigmentation, tiam sis tsis txaus rau kaj noo xim. Nws puv cov xim ntawm "ib nrab."

Tej yam tshwm sim yog pub los ntawm intermediate hom

Tej tiav qub txeeg qub teg tracked zoo nyob rau hauv ib tug nce mus nce los qhia cov tsos mob:

1. Cov xim siv. William Bateson, hla dub thiab dawb cov poj qaib Andalusian tsiaj yug nrog nyiaj plaub. Nyob rau hauv lub ntsiab txhais ntawm lub qhov muag tib iris xim plhaub tseem yog tam sim no active mechanism.
2. Lub degree ntawm heev ntawm cov tsos mob. tib neeg cov plaub hau yog tseem txiav txim siab tsis tiav qub txeeg qub teg kev zoo losis phem. Genotype AA muab curly plaub hau, ib tug - ncaj, thiab cov neeg uas muaj ob qho tib si alleles muaj laim ntoom plaub hau.
3. Ntsuas ntsuas. nplej pob ntseg ntev yog pub rau lub hauv paus ntawm tsis tiav dominance.

Nyob rau hauv lub F2 tiam phenotypes tooj coincides nrog lub xov tooj ntawm genotypes uas characterizes tsis tiav dominance. Test ntoo khaub lig los mus txiav txim lub hybrids tsis xav tau, vim hais tias lawv zoo sib txawv los ntawm lub hom huv si kab.

Cleavage ntawm hla tej yam tshwm sim

Ua kom tiav thiab tsis tiav dominance zoo li noob sis tshwm sim nyob rau hauv raws li cov kev laij cov kev cai ntawm Mendel. Nyob rau hauv rooj plaub thawj, qhov ratio nyob rau hauv lub F2 phenotypes (3: 1) tsis coincide nrog tus piv ntawm cov xeeb ntxwv genotypes (1: 2: 1) raws li phenotypically ob peb ua ke ntawm AA thiab AA alleles tshwm sim tau tib yam. Ces tsis tiav dominance - ib tug match nyob rau hauv F2 proportions ntawm txawv genotypes thiab phenotypes (1: 2: 1).

Nyob rau hauv pos nphuab coloring kuv pub ib xyoo rau lub hauv paus ntawm tsis tiav dominance. Yog hais tias hla ib tug nroj tsuag nrog rau liab berries (AA) thiab nroj tsuag nrog dawb berries - genotype AA, thawj tiam ntawm cov nroj tsuag tag nrho cov tau txais yuav dais txiv hmab txiv ntoo nrog ib tug liab xim (AA).

Hybrids yog hla los ntawm F1, F2 nyob rau hauv lub thib ob tiam xeeb leej xeeb ntxwv tau ib tug kev sib raug zoo uas coincides nrog hais tias genotype: 1AA + + 2Aa 1AA. 25% ntawm cov nroj tsuag ntawm lub thib ob tiam yuav muab cov liab thiab uncolored txiv hmab txiv ntoo, 50% ntawm cov nroj tsuag - liab.

Zoo ib yam li yuav tsum muaj cai nyob rau hauv ob tiam los hla ntshiab kab nrog paj zoo zoo nkauj hmo ntuj Corolla liab doog thiab dawb xim.

Nta ntawm qub txeeg qub teg nyob rau hauv cov ntaub ntawv ntawm lub neej no noob

Nyob rau hauv tej rooj plaub, qhov ratio ntawm phenotypes ntawm cov xeeb ntxwv yog ib qhov nyuaj los mus txiav txim yuav ua li cas noob INTERACTIONS. Nyob rau hauv lub thib ob tiam ntawm tsis tiav dominance splitting nws txawv ntawm cov kev tsim 1: 2: 1 thiab 3: 1 - nyob rau hauv tag nrho. Qhov no tshwm sim thaum ib tug tseem ceeb los yog recessive kev zoo losis phem nyob rau hauv lub homozygous lub xeev muab ib tug phenotype uas yog tsis tau tshaj nrog lub neej (tuag noob).

Nyob rau hauv astrakhan yaj gray xim me nyuam mos lambs uas yog homozygous rau lub hom allele xim, tuag vim lub fact tias qhov no genotype yog ib tug ua txhaum ntawm lub plab.

Nyob rau hauv tib neeg, ib qho piv txwv ntawm lub neej no tseem ceeb hauv daim ntawv ntawm cov noob - brachydactyly (korotkopalost). Seb mob kuaj nyob rau hauv nyob rau hauv cov ntaub ntawv ntawm lub heterozygous genotype, thaum lub sij hawm tseem ceeb homozygotes tuag thaum ntxov ntawm me nyuam hauv plab kev loj hlob.

Tej zaum yuav tuag recessive alleles. Sickle cell anemia ua, nyob rau hauv cov ntaub ntawv ntawm ob recessive alleles nyob rau hauv lub genotype, tsim erythrocytes hloov. Ntshav yuav tsis zoo yuav txuas pa, thiab 95% ntawm cov me nyuam nrog rau qhov no anomaly raug tua los ntawm cov pa starvation. Nyob rau hauv heterozygotes hloov hauv daim ntawv ntawm cov ntshav liab yog tsis cuam tshuam rau tej qhov twg nyob rau hauv lub nqi.

Cleavage nyob rau hauv lub xub ntiag ntawm tej yam tshwm sim ntawm tuag noob

Nyob rau hauv thawj tiam, thaum hla AA x ib lub neej no yuav tsis tshwm sim, vim hais tias tag nrho cov xeeb leej xeeb ntxwv yuav muaj cov AA genotype. Muab piv txwv ntawm cov cim ntawm splitting rau lub thib ob tiam neeg mob tuag noob:

Nws yog ib qho tseem ceeb kom to taub tias cov nyhuv thaum ob leeg tau hlawv tsis tiav dominance, thiab cov nyhuv ntawm suppressing ib nrab feature tshwm sim los ntawm cov kev sis raug zoo ntawm noob khoom.