Mienzaniso yeMibvunzo Inokurukura Mutemo waMendel weKutsauka Kunooneka
Pendauluan
Mitemo yaMendel yenhaka yemajini yave hwaro hwemajini emazuva ano. Gregor Mendel, mumongi wekuCzech, ndiye akatanga mitemo yekutanga inotsanangura kuti hunhu hunogarwa sei kubva kuchizvarwa kuenda kune chimwe kuburikidza nekuyedza pazvirimwa zvepizi. Zvisinei, munyika yakaoma yebiology, kutsauka kubva pamitemo iyi mikuru kunowanzoitika. Chimwe chiitiko chakadaro kutsauka kuri pachena kubva pamitemo yaMendel.
Kutsauka kuri pachena kubva kumitemo yaMendel kunoitika kana maitiro ekugara nhaka kwemajini asingaenderane nemitemo yekare yaMendel. Kutsauka uku kunogona kukonzerwa nezvinhu zvakati wandei, zvakaita sekudyidzana kwemajini, hukama hwakaoma hwe allelic, nezvimwewo. Chinyorwa chino chichakurukura mienzaniso yakati wandei yematambudziko ane chekuita nekutsauka kuri pachena kubva kumitemo yaMendel uye maitiro ekuiongorora.
Muenzaniso Mubvunzo 1: Epistasis
Epistasis chiitiko umo mhedzisiro yejini rimwe inovharwa nerimwe jini risiri allele yaro. Izvi zvinowanzo konzera phenotypes dzisingaenderane nemutemo waMendel wekuparadzanisa. Heano mimwe mienzaniso yematambudziko ane chekuita ne epistasis:
Mubvunzo: Mumaruva, ruvara rwemaruva runobva mumajini maviri. Gene A, kana ichishanda, inogadzira pigment tsvuku. Gene B, kana ichishanda, inodiwa kuti gene A ishande. Kana gene B isipo kana kuti isingabatsiri, gene A haizobudisi pigment kunyangwe iripo. Muchirimwa chine genotype AaBb, mukana wekuwana chirimwa chine maruva matsvuku ndeupi?
Kukurukurirana: Muchiitiko ichi, gene B inoenderana negene A. Kuti ruva rive dzvuku, panofanira kunge paine allele A inoshanda kanenge kamwe chete uye allele B inoshanda kamwe chete. Ngationgororei misanganiswa ye genotype inogona kutsigira izvi:
– Mhando yeAaBb inozogadzira mhando tsvuku, nekuti majini ese A neB anoshanda.
– Mimwe misanganiswa yakaita seAabb kana aaBb haizoburitse maruva matsvuku nekuti inoda kudyidzana pakati pemajini maviri aya.
Mikana yekuti chirimwa chine maruva matsvuku chive musanganiswa we alleles A ne B dzinoshanda. Kana tikagadzira tafura yemajini yeAaBb x AaBb, mukana wekuti chirimwa chine maruva matsvuku (chinonyanya kukosha mumajini ese ari maviri) i9 kubva pa16. Saka, mukana wekuti maruva matsvuku awane 9/16.
Muenzaniso Mubvunzo 2: Inouraya Allele
Allele inouraya iallele ine mhedzisiro inouraya pamunhu anoitakura, kazhinji kana iri homozygous. Rudzi urwu rweallele inouraya runogona kukanganisa huwandu hunotarisirwa hwe phenotypic zvichienderana nemutemo waMendel.
Mubvunzo: Mumakonzo, jini remvere dzeyero (Y) ndiro rinotonga jini remvere dzegrey (y). Zvisinei, allele yeYY inouraya, zvichikonzera kufa nguva isati yakwana. Kana makonzo maviri ane heterozygous (Yy) akabatana, chii chinonzi vible phenotypes?
Kukurukurirana: Mumuchinjikwa weYy x Yy, mutemo waMendel wekare ungafanotaura chiyero che3:1, asi munyaya iyi tinofanira kufunga nezvemhedzisiro inouraya:
– YY: Inouraya, haizoberekwi
- Yy: Yero
– yy: Gireyi
Vanhu chete Yy na yy ndivo vachapona:
– Huwandu hwevanhu vane Yy (yero) zvikamu zviviri muzvitatu zvehupenyu hwese (2 kubva pa3).
– Huwandu hwevanhu vane makore 12 kusvika ku13 (grey) chikamu chimwe muzvitatu chevanhu vese vanorarama (1 pa3).
Chiyero che phenotypic chemakonzo akapona chaive 2:1.
Muenzaniso Mubvunzo 3: Kubatana kweMajini
Majini ari pedyo nepedyo pane chromosome imwe chete anogona kusatevedzera mutemo waMendel wekuparadzanisa kwakazvimirira nekuda kwetsika yavo yekugara nhaka pamwe chete; izvi zvinozivikanwa sekubatana.
Mubvunzo: Munhunzi dzemichero, majini eruvara rwemuviri (dema kana brown) uye saizi yemapapiro (yakajairika kana yakanonoka) ari pachromosome imwe chete uye akabatana. Semuenzaniso, genotype yeBbNn inoratidza hukama pakati pealleles B (dema) naN (yakajairika) nab (brown) nan (yakanonoka). Kana nhunzi mbiri dzeBbNn dzikapatsanurwa, phenotypes dzinozobuda dzichaenzaniswa sei kana chiyero chekuyambuka chiri 20%?
Kukurukurirana: Kana majini ari pachromosome imwe chete akabatana, ma alleles emajini ari pedyo anowanzo ungana pamwe chete panguva yekuumbwa kwe gamete. Zvisinei, kusanganiswa kana kuyambuka kunogona kuaparadzanisa.
- Sezvo paine mukana we20% wekuyambuka, vamwe 80% vanozotevera maitiro akajairwa ekubatanidza.
- Pa80% inotevera maitiro ekubatanidza, kusanganisa magametes kuchaburitsa mamwe ma phenotypes, chero ari pedyo.
– Mhedzisiro yekuyambuka (20%) inobereka vana vane ma phenotype matsva.
Ngationgororei musanganiswa we phenotypes:
– Nekubatana kwakawanda (80%): Ma phenotypes anotonga anoenderana nevabereki (akajairika matema uye mabrown asina kusimba).
– Nekusanganiswa kwemavara (20%): Mhando itsva dzemavara matema akaremara uye mabrown akajairwa anoonekwa.
Kuti tiwane huwandu hwe phenotype, tinoita kuverenga zvichibva pahuwandu uhwu.
Mhedziso
Kutsauka kuri pachena kubva kumitemo yaMendel kunova kwakakosha kunzwisisa kana tichitarisa magene akaomarara. Epistasis, maallele anouraya, uye gene linkage inongova mienzaniso mishoma yemamiriro ezvinhu anokanganisa maitiro anogarwa nhaka uye anowanzo konzera phenotype ratios dzakasiyana nedzinotarisirwa zvichibva pamitemo yaMendel iri nyore. Nekunzwisisa kutsauka uku, tinogona kufanotaura nekunzwisisa nhaka yemagene muzvisikwa. Kudzidza nyaya idzi kunokosha mukuvandudza kunzwisisa kwakadzama kwemagene nebiology yekushanduka-shanduka.
