Nondisjunction, uas chromosomes tsis sib npaug sib npaug, tuaj yeem tshwm sim hauv meiosis I (thawj kab), meiosis II (kab ob), thiab mitosis (peb kab). Cov kev sib cais tsis sib xws no tuaj yeem tsim cov menyuam ntxhais nrog tus lej chromosome uas tsis tau xav txog, hu ua aneuploids.
Puas mitosis tsis muaj kev cuam tshuam?
Nondisjunction tuaj yeem tshwm sim thaum lub sijhawm anaphase ntawm mitosis, meiosis I, lossis meiosis II. … Hauv kev tsis sib haum xeeb, kev sib cais tsis tshwm sim ua rau ob tus muamchromatids lossis homologous chromosomes raug rub mus rau ib tus ncej ntawm tes.
Puas yog kev tsis sib haum xeeb ntau dua hauv mitosis lossis meiosis?
1 NONDISJUNCTION
Nondisjunction txhais tau hais tias ib khub ntawm homologous chromosomes tau ua tsis tiav los yog cais ntawm anaphase kom ob leeg chromosomes ntawm khub dhau mus rau tib tus ntxhais cell. Qhov no tej zaum yuav tshwm sim feem ntau hauv meiosis, tab sis nws yuav tshwm sim hauv mitosis los tsim ib tus neeg mosaic.
Puas muaj kev tsis sib haum xeeb hauv meiosis?
Muaj peb daim ntawv ntawm kev tsis sib haum: tsis ua haujlwm ntawm ib khub ntawm homologous chromosomes cais hauv meiosis I, tsis ua haujlwm ntawm tus viv ncaus 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).
Thaum twg tsis muaj kev cuam tshuam tshwm sim thaum lub sij hawm meiosis?
Qee zaum thaum anaphase, chromosomes yuav tsis cais kom raug. Nco ntsoov, qhov no yog hu ua nondisjunction. Qhov no tuaj yeem tshwm sim thaum meiosis I lossis meiosis II. Yog tias tsis muaj kev cuam tshuam tshwm sim thaum lub sij hawm anaphase I ntawm meiosis I, qhov no txhais tau hais tias tsawg kawg ib khub ntawm homologous chromosomes tsis sib cais.
