Ib qho yooj yim noob caj noob ces: recessive kev zoo losis phem - nws yog ...

Recessive kev zoo losis phem - ib tug kev zoo losis phem uas tsis manifest nws tus kheej yog hais tias muaj yog ib tug tseem ceeb allele genotype ntawm tib kos npe rau. Yuav kom to taub zoo dua no txhais, cia nrog txoj kev cov cai tej yam tshwm sim tshwm sim nyob rau kev tshuaj ntsuam genetic theem.

Ib me ntsis ntawm kev tshawb xav

Txhua feature nyob rau hauv tib neeg yog kho los ntawm ob noob, alleles, ib tug ntawm txhua tus niam txiv. Alleles raug muab faib mus rau hauv hom thiab recessive. Yog hais tias ib tug gamete muaj hom thiab recessive allele, lub phenotype yuav tshwm sim tseem ceeb. Qhov no txoj ntsiab cai hauv daim duab ib tug piv txwv yooj yim ntawm ib tug lub tsev kawm ntawv cov hoob kawm biology yog ib tug niam txiv xiav ob lub qhov muag, thiab lwm yam - xim av, ces tus me nyuam yog yuav tsum xim av ob lub qhov muag, raws li xiav - recessive kev zoo losis phem. Qhov no txoj cai yog txhais tau hais tias nyob rau hauv lub genotype ntawm ob xim av-eyed cov niam txiv coj allele hom. Cia xim av ob lub qhov muag rau cov lus teb Ib tug noob rau xiav - ib tug. Ces, thaum hla ob peb tau xaiv:

P: AA x ib;

F1: ib tug ib tug ib AA AA.

Tag nrho heterozygous cov me nyuam, thiab tag nrho cov manifested hom - xim av ob lub qhov muag.

Ob txhais kev xaiv:

P: ib tug ib tug x ib;

F1: AA, AA, aa, aa.

Nrog rau qhov no hla thiab manifests ib tug recessive kev zoo losis phem (no cov kob xiav ob lub qhov muag). Qhov ntau uas ib tug me nyuam yuav tsum muaj ib tug xiav-eyed, - 50%.

Ib yam li ntawd pub albinism (pigmentation mob), dig muag, hemophilia. Qhov no recessive sijhawm ntawm tus txiv neej, uas yuav tshwm sim xwb nyob rau hauv lub qhaj ntawv ntawm ib tug tseem ceeb allele.

Nta recessive sijhawm

Muaj ntau recessive sijhawm muaj arisen raws li ib tug tshwm sim ntawm kev tshuaj ntsuam genetic change. Cov txheejtxheem, piv txwv li, qhov kev paub ntawm Thomas Morgan nrog lub txiv hmab txiv ntoo ya Drosophila. Lub qhov muag xim rau yoov - liab thiab ib co dawb-eyed yoov ua yog ib tug hloov nyob rau hauv lub X chromosome. Thiab muaj ib tug recessive, pw ua niam txiv-txuas.

Hemophilia A thiab dig muag kuj zwm rau recessive sijhawm, pw ua niam txiv-txuas.

Xav txog hla recessive sijhawm piv txwv li xim dig muag. Piv txwv hais tias ib tug noob lub luag hauj lwm rau lub qub xim xaav, - X, ib tug mutant - X ^d. Crossbreeding yog raws li nram no:

P: XX X X ^d Y;

F1: XX ^{d, d} XX, XY, XY.

Uas yog, yog hais tias tus txiv yog xim dig muag, thiab nws niam yog nyob rau hauv zoo noj qab haus huv, tag nrho cov me nyuam yuav tsum noj qab nyob zoo, tab sis tus hluas nkauj yuav tsum muaj ntawm cov xim dig muag noob, uas yog ib tug 50% lub sij hawm yuav tsum tau muaj nyob rau hauv lawv cov txiv neej cov me nyuam. Cov poj niam colorblindness yog heev tsawg, vim hais tias cov noj qab nyob zoo X chromosome compensates rau lub mutant.

Lwm yam kev noob sis

Cov yav tas los piv txwv nrog rau xim ntawm nws ob lub qhov muag - ib qho piv txwv ntawm tag nrho cov domination, uas yog, qhov tseem ceeb noob yog kiag li yaus poob deb tuag tawm lub recessive noob. Kos npe rau manifested nyob rau hauv lub genotype sau raws nkaus Ii mus rau lub hom allele. Tab sis muaj tej lub sij hawm thaum lub hom noob yog tsis tau kiag li suppresses recessive, thiab cov xeeb ntxwv yog muaj ib tug ntoo khaub lig - ib tug tshiab feature (kodominirovanie), los yog manifest lawv tus kheej ob noob (tsis tiav dominance).

Kodominirovanie - ib tug tsawg phenomenon. Nyob rau hauv tib neeg kodominirovanie tsuas pom qub txeeg qub teg ntawm cov ntshav pab pawg. Cia ib tug ntawm cov niam txiv lub thib ob pab pawg neeg ntawm cov ntshav (AA), lub thib ob - tus pab thib peb (BB). Ob A thiab B yam ntxwv tseem ceeb. Thaum hla, peb pom tias tag nrho cov me nyuam muaj ntshav plaub pab pawg neeg, coded li AB. Uas yog tshwm nyob rau hauv lub phenotype ntawm ob cim.

Tsis tas li ntawd pub xim ntawm ntau flowering nroj tsuag. Thaum koj hla lub liab thiab dawb rhododendron, qhov tshwm sim muaj peev xwm yuav ob leeg liab thiab dawb thiab lis-xim paj. Txawm tias liab yog hom, thiab nyob rau hauv cov ntaub ntawv no, nws tsis suppress lub recessive kev zoo losis phem. No sis nyob rau hauv uas ob yam ntxwv tshwm sim Attendance kwm genotype.

Lwm yam txawv piv txwv li muaj feem xyuam rau kodominirovaniem. By hla liab thiab dawb cosmos ib tug tshwm sim tej zaum yuav liab. Cov liab xim yog ib tug ntawm tsis tiav dominance, thaum lub hom allele ua num ua ke nrog recessive. Yog li, ib tug tshiab intermediate feature.

uas tsis yog-allelic sis

Nws yog stipulated hais tias cov tib neeg genotype tsis tiav dominance yog tsis peculiar. tsis tiav dominance mechanism yog tsis muaj feem xyuam rau cov xim qub txeeg qub teg. Yog hais tias ib tug ntawm cov niam txiv ntawm daim tawv nqaij yog tsaus, lwm lub teeb, thiab tus me nyuam - tsaus ntuj nti, intermediate kev xaiv, nws tsis yog ib qho piv txwv ntawm tsis tiav dominance. Nyob rau hauv cov ntaub ntawv no nyuam qhuav tshwm sim sis nonallelic noob.