Nondisjunction in Translocation Heterozygotes Cov kab mob heterozygous rau kev hloov pauv chromosome reciprocal yog ua rau ntau zaus ntawm kev txawv txav meiotic disjunction, suav nrog nondisjunction.
Yuav ua li cas yog lub npe nondisjunction hom sib txawv?
Muaj peb hom kev tsis sib haum: tsis ua haujlwm ntawm ib khub ntawm homologous chromosomes cais hauv meiosis I, tsis ua haujlwm ntawm tus muam chromatids cais thaum lub sijhawm meiosis II, thiab tsis ua haujlwm ntawm tus muam chromatids cais thaum lub sij hawm mitosis. Nondisjunction ua rau cov menyuam ntxhais nrog cov lej chromosome txawv txav (aneuploidy).
kev tsis sib haum yog dab tsi?
1 NONDISJUNCTION
Nondisjunction txhais tau hais tias ib khub ntawm homologous chromosomes tsis tau cais lossis cais ntawm anaphase kom ob leeg chromosomes ntawm khub dhau mus rau tib tus ntxhais cell Qhov no feem ntau tshwm sim hauv meiosis, tab sis nws yuav tshwm sim hauv mitosis los tsim ib tus neeg mosaic.
Dab tsi yog ob qho piv txwv ntawm kev tsis sib haum xeeb?
Nondisjunction ua rau yuam kev ntawm tus lej chromosome, xws li trisomy 21 (Down syndrome) thiab monosomy X (Turner syndrome). Nws kuj yog ib qho ua rau muaj kev rho menyuam ntxov ntxov.
Yuav ua li cas thiaj tsis sib haum?
Hauv kev tsis sib haum, kev sib cais tsis tshwm sim ua rau ob tus muam chromatids lossis homologous chromosomes raug rub mus rau ib tus ncej ntawm tes. Mitotic nondisjunction tuaj yeem tshwm sim vim qhov tsis ua haujlwm ntawm topoisomerase II, condensin, lossis cais.
