Sau kom tiav dominance thiab lwm yam kev noob sis

Muaj ntau ntawm peb tau hnov txog hom thiab recessive noob - ib co muab zais rau hauv peb genome nucleotide chains, uas yog lub luag hauj lwm rau cov noob sijhawm. Yuav ua li cas lawv INTERACTIONS? Yuav ua li cas yog lub dominance thiab yuav ua li cas nws tshwm sim? Yog vim li cas recessive alleles yeej tsis suppressed los ntawm hom? Cov teeb meem yog zaum txij li thaum lub foundations ntawm noob.

Keeb kwm ntawm kev tshawb fawb

allele sis yog ib txwm zoo txaus siab rau geneticists. Kev tshawb fawb pom tau hais tias muaj ntau hom kev noob sis - tag dominance, superdominance, ntau yam allelism, tsis tiav dominance thiab kodominirovanie.

Rightfully dubbed leej txiv ntawm niaj hnub noob caj noob ces, Gregor Mendel yog thawj los ua xav nyob rau hauv cov kev cai ntawm cov kis ntawm cov roj ntsha sijhawm. Thaum lub sij hawm nws nto moo thwmsim rau lub hybridization ntawm noob taum nroj tsuag, Mendel pom tias cov hla kev daj thiab ntsuab taum mog tsis ua nyob rau hauv ib nrab kev zoo losis phem. Nyob rau hauv thawj tiam tag nrho cov muaj daj noob taum. Mendel nws tus kheej yog hais tias nws yuav tsis piav cov kev tshwm sim ntawm nws ci ntsa iab xyaum ua tej yam. Lub theoretical lub hauv paus tuaj npaum li cas tom qab ntawd, tom qab lub rooj txhawb siab ntawm kev txaus siab nyob rau hauv noob caj noob ces thiab tus foundations ntawm cov elementary units ntawm caj - ntawm cov noob. Qhov ntawd yog nyob ntawm nws cov xim ntawm taum mog, qhov ntswg lawm, qhov muag xim, qhov siab, muaj kev tshuaj ntsuam genetic kab mob nyob rau hauv tib neeg.

Cia peb rov qab mus rau qhov xyaum ua tej Mendel. Rau cov daj xim sau raws nkaus Ii taum mog A noob rau ntsuab - ib tug. Thaum hla ob tug sib txawv ntshiab kab splitting yuav raws li nram no:

P: AA x ib

F1: ib tug ib tug ib AA AA

Txawm tias muaj tseeb hais tias nyob rau hauv lub genotype ntawm lub resulting raws li ib tug tshwm sim ntawm tus ntoo khaub lig-yug me nyuam ntawm cov nroj tsuag yog ib tug noob thiab ib tug daj thiab ntsuab xim, nws thiaj li manifested tsuas daj. Nyob rau hauv lwm yam lus, cov hom kev zoo losis phem yog recessive kiag li poob rau tawm. Ib yam li ntawd, pub thiab zoo ntawm peas - tus prevailed tshaj wrinkled. Nws yog ib qhov piv txwv li, thiab qhia txog cov ua tiav dominance ntawm noob - cov hluav ntawm lub hom kos npe rau nyob rau hauv lub xub ntiag ntawm ib tug recessive genotype nyob rau hauv ob qho tib si ntawm lawv.

Piv txwv ntawm tag nrho dominance

Crossbreeding txawv tsob nroj xim - tsis tus tsuas yog qhov chaw uas ua kom tiav dominance manifested. Piv txwv ntawm no hom ntawm kev sis raug zoo muaj peev xwm ua rau thiab los ntawm lub tshav pob ntawm tib neeg noob caj noob ces: yog hais tias ib tug niam txiv muaj xim av ob lub qhov muag, qhov thib ob - cov kob xiav, thiab neb ob leeg yeej homozygous rau cov cim, ces tag nrho cov me nyuam yuav muaj xim av ob lub qhov muag.

Ib yam li ntawd, lub xub ntiag ntawm pub v tau, polydactyly, freckles, cov plaub hau dub. Tag nrho cov tej yam tshwm sim yog hom, thiab yuav tsis cia tshwm sim nyob rau hauv lub phenotype yog recessive.

Sau kom tiav dominance ntawm kuj zoo kawg tseem ceeb nyob rau hauv lub qub txeeg qub teg ntawm kev tshuaj ntsuam genetic kab mob. Feem ntau ntawm lawv (Tay-Sachs kab mob, Urbach-Vite kab mob Gunther tus kab mob), yog pub nyob rau hauv ib tug autosomal recessive yam, uas yog, nyob rau hauv lub xub ntiag ntawm lub genotype ntawm ib tug ib txwm noob (hom) mutant allele tsis qhia nws tus kheej.

uas ua tsis tiav dominance

Uas ua tsis tiav dominance - ib hom ntawm noob sis yog feem ntau pom nyob rau hauv cov xwm. Thaum nws recessive allele yog suppressed yog tsis tau kiag li tseem ceeb thiab cov phenotype tshwm tshiab, interim tag. Ib tug piv txwv ntawm tsis tiav dominance - nrag cosmos paj. Yog hais tias tus nroj tsuag yog tus ntoo khaub lig liab thiab dawb, thawj tiam cleavage phenotype yuav raws li nram no: 1 (AA): 2 (AA): 1 (ib). Hais tias yog, paj yog xim liab, ib tug dawb thiab ob liab. Lub xeem yog ib qho piv txwv ntawm tsis tiav dominance, raws li ib tug tseem ceeb kev zoo losis phem, liab, suppressed recessive incompletely. Cov no muaj nyob rau hauv lub cev cov nyhuv ntawm ob noob.

Uas ua tsis tiav dominance yog cov yam ntxwv xwb tsis rau tus cosmos, tab sis kuj rau ntau lwm yam paj: snapdragons, tulips, carnations.

superdominance

Superdominance - nthuav thiab dog dig paradoxical kev sib tshuam hom noob, nyob rau lub phenotype nyob rau hauv heterozygous kab mob (BB) hom noob behaves ntau mob siab heev tshaj nyob rau hauv lub phenotype ntawm homozygous (BB). Superdominance tshwm sim nyob rau hauv cov xwm raws li feem ntau raws li tag nrho dominance. Ib qho piv txwv yog HBB noob hloov los ntawm cov uas thiaj li muaj qhov pheej hmoo ntawm kev cog lus malaria.

Kodominirovanie

Muaj ntau ntau nthuav noob sis hom, thiab ib tug ntawm lawv - kodominirovanie. Nyob rau hauv rooj plaub no tus tseem ceeb allele tsis npog los yog suppress lub recessive phenotype nyob rau hauv ob qho tib si yam ntxwv mus rau ib tug tej yam raws li sau nws tus kheej.

Qhov yooj yim txoj kev uas yuav to taub lub phenomenon kodominirovaniya cov piv txwv ntawm cov liab-dawb rhododendron paj, los yog zoo nkauj hmo ntuj. Tej coloring yog tau los ntawm hla liab thiab dawb paj, thiab txawm hais tias cov liab xim yog hom, nws tsis daig caj pas lub allele lub luag hauj lwm rau cov dawb xim. Thiab ua ib tug txawv txawv ob-laus xim nrog rau cov AA genotype.

Ib qho piv txwv yog lub mechanism ntawm qub txeeg qub teg kodominirovaniya ntshav pab pawg. Piv txwv ib leej niam leej txiv ob ntshav pab pawg neeg (kuv ^A Kuv ^A), qhov thib peb thiab lub thib ob (Kuv ^B Kuv ^B), ces tus me nyuam yuav muaj ib tug plaub pab pawg neeg uas tsis yog intermediate ntawm lub thib ob thiab thib peb, nrog genotype kuv ^A Kuv ^B.