Chiasmata yog qhov tseem ceeb rau qhov txuas ntawm homologous chromosomes rau cov ncej ntxaiv (bipolar txuas)thiab lawv cov kev sib cais tom qab rau cov ncej rov qab thaum lub sij hawm meiosis I.
Dab tsi yog qhov tseem ceeb ntawm chiasmata?
Chiasmata yog lub ntsiab lus uas sawv cev lossis qhia qhov txuas ntawm homologous chromosomes ua ke. Cov qauv no yog tsim thaum hla ntawm cov tsis yog tus muam chromatids tshwm sim. Chiasmata yog ib qho tseem ceeb vim nws yog lub ntsiab lus uas cov noob ntawm niam thiab txiv sib pauv thiab ua rau rov ua dua.
chiasmata yog dab tsi thiab nws lub luag haujlwm hauv kev hla dhau?
chiasmata) yog lub ntsiab lus ntawm kev sib cuag, qhov sib txuas ntawm lub cev, nruab nrab ntawm ob (tsis yog tus muam) chromatids belongs rau homologous chromosomes. … Cov ntsiab lus ntawm kev hla dhau los ua pom zoo li chiasma tom qab lub synaptonemal complex dissembles thiab homologous chromosomes me ntsis sib nrug ntawm ib leeg.
Vim li cas synapsis thiab chiasmata tseem ceeb meiosis?
Lub hauv paus ua haujlwm ntawm kev sib tham yog li ntawd kev txheeb xyuas homologues los ntawm kev ua khub, ib kauj ruam tseem ceeb rau kev ua tiav meiosis. Cov txheej txheem ntawm DNA kho thiab chiasma tsim uas tshwm sim tom qab synapsis muaj qhov tshwm sim ntawm ntau theem, los ntawm cellular ciaj sia mus txog rau kev cuam tshuam rau evolution nws tus kheej.
Vim li cas thiaj ua chiasmata?
Chiasmata yog cov qauv chromatin tshwj xeeb uas txuashomologous chromosomes ua ke kom txog thaum anaphase I (Fig. 45.1 thiab 45.10). Lawv tsim ntawm qhov chaw uas programmed DNA tawg tsim los ntawm Spo11 tau dhau los ua txoj hauv kev rov ua dua tshiab los tsim crossovers.
