Thaum meiosis, homologous chromosomes (1 ntawm txhua tus niam txiv) ua khub raws lawv qhov ntev. Chromosomes hla ntawm cov ntsiab lus hu ua chiasma. Ntawm txhua chiasma, cov chromosomes tawg thiab rov ua dua, ua lag luam qee yam ntawm lawv cov noob. Qhov kev rov ua dua no ua rau muaj kev hloov pauv caj ces.
Yuav ua li cas rov ua kom muaj kev hloov pauv?
Homologous Recombination
paired chromosomes los ntawm txiv neej thiab poj niam niam txiv sib dhos kom zoo sib xws DNA sib lawv liag los ntawm khub chromosomes hla ib leeg. Kev hla dhau qhov tshwm sim hauv kev sib hloov ntawm cov khoom siv caj ces thiab yog ib qho tseem ceeb ntawm kev hloov caj ces pom ntawm cov xeeb ntxwv.
Qhov cuam tshuam ntawm kev sib koom ua ke yog dab tsi?
Recombination kuj tau hloov kho los ntawm ntau yam ntawm ib puag ncig stimuli, suav nrog kub [5] thiab mob [6]. Recombination muaj cov txiaj ntsig zoo rau kev noj qab haus huv: piv txwv li, hauv tib neeg, kev hloov pauv ntawm kev sib txuas ua ke tuaj yeem ua rau chromosomal txawv txav, txo qis fertility thiab kab mob [7].
Dab tsi yog recombination Vim li cas thiaj tseem ceeb?
Tshaj tawm nws lub luag haujlwm hauv meiosis, kev rov ua dua yog qhov tseem ceeb rau cov hlwb somatic hauv eukaryotes vim nws tuaj yeem siv los pab kho DNA puas, txawm tias thaum tawg cuam tshuam nrog ob txoj hlua ntawm ob. helix. … Tom qab ntawd, ib zaug ua ke, DNA tshiab no tuaj yeem muab tso rau hauv cov DNA uas tawg, yog li kho nws.
Dab tsi yog qhov txawv ntawm kev sib koom ua kethiab mutation?
Mutations muab thawj qhov chaw ntawm ntau haiv neeg los ntawm kev hloov cov haujlwm tshwj xeeb thiab kev sib txuas ua ke ntawm cov kev hloov pauv los ntawm pauv cov caj ces txuas ntxiv txhawm rau nce cov caj ces hloov pauv.
