Nondisjunction: Ua tsis tiav ntawm cov chromosomes sib cais (kom disjoin) thaum lub sijhawm faib ntawm tes, kom ob qho tib si chromosomes mus rau ib tus ntxhais cell thiab tsis mus rau lwm tus. Nondisjunction ua rau yuam kev hauv chromosome tooj, xws li trisomy 21 (Down syndrome) thiab monosomy X (Turner syndrome).
Kev tsis sib haum xeeb yog dab tsi thiab nws tshwm sim nyob qhov twg?
Nondisjunction tshwm sim thaum homologous chromosomes lossis tus muam chromatids tsis cais thaum lub sijhawm meiosis, ua rau tus lej chromosome txawv txav. Kev tsis sib haum xeeb tuaj yeem tshwm sim thaum meiosis I lossis meiosis II.
kev tsis sib haum xeeb tshwm sim li cas?
Nondisjunction tshwm sim thaum homologous chromosomes (meiosis I) lossis tus muam chromatids (meiosis II) tsis cais thaum lub sijhawm meiosisIb tus neeg uas tsim nyog tus lej ntawm chromosomes rau lawv hom hu ua euploid; Hauv tib neeg, euploidy sib raug rau 22 khub ntawm autosomes thiab ib khub ntawm kev sib deev chromosomes.
kev tsis sib haum xeeb ua rau dab tsi?
Nondisjunction hauv meiosis tuaj yeem ua rau cev xeeb tub lossis yug menyuam nrog chromosome ntxiv hauv txhua lub hlwb, qhov tsis sib haum xeeb hauv mitosis yuav ua rau mosaicism nrog ob lossis ntau lub xovtooj ntawm tes.. Aneuploidy kuj tseem tuaj yeem tshwm sim los ntawm anaphase lag.
Kev tsis sib haum xeeb tshwm sim nyob qhov twg hauv lub voj voog ntawm tes?
Nondisjunction, uas chromosomes tsis sib luag, tuaj yeem tshwm sim hauv meiosis I (ib kab), meiosis II (kab ob), thiab mitosis (kab peb). 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.
