Yog li ntawd, kev tsis sib haum xeeb yuav tsum tshwm sim hauv leej niam. Nco ntsoov tias thaum lub sij hawm meiosis kuv, muab tsis muaj crossover ntawm cov noob thiab cov centromere, allelic lwm txoj kev sib cais ntawm ib leeg. Thaum lub sij hawm meiosis II, zoo tib yam alleles ntawm tus muam chromatids cais.
Puas muaj kev tsis sib haum xeeb tshwm sim hauv txiv neej lossis poj niam?
Txoj kev xav, kev tsis sib haum xeeb yuav tshwm sim hauv cov txiv neej thiab poj niam cov kab mobntawm thawj lossis thib ob meiotic faib thiab yuav ua rau muaj ntau yam tsis sib cais. hom hauv progeny.
Nyob rau hauv leej niam leej txiv thiab meiotic faib tsis tau tshwm sim?
Nondisjunction tshwm sim thaum homologous chromosomes (meiosis I) lossis tus muam chromatids (meiosis II) tsis caisthaum lub sijhawm meiosis.
Puas yog Down syndrome niam lossis txiv tsis muaj kev cuam tshuam?
Trisomy 21 lossis Down Syndrome (DS) yog ib qho ntawm cov chromosomal abnormalities feem ntau. Feem ntau ntawm tag nrho trisomy 21 yog tshwm sim los ntawm chromosomal nondisjunction tshwm sim thaum niam txiv meiotic division (∼90%).
Qhov tsis muaj kev cuam tshuam tshwm sim rau Turner's syndrome?
Nondisjunction tej zaum yuav tshwm sim thaum lub sij hawm meiosis I los yog meiosis II. Aneuploidy feem ntau ua rau muaj teeb meem loj xws li Turner Syndrome, ib qho monosomy uas cov poj niam yuav muaj tag nrho lossis ib feem ntawm X chromosome.
