Qhov Tseem Ceeb Qhov txawv - Bivalent vs Chiasmata hauv Meiosis
Meiosis yog txheej txheem ntawm cell faib ua raws li gamete hlwb. Thaum lub sij hawm meiosis, tus lej chromosome raug txo los ntawm ib nrab txhawm rau tswj tus lej chromosome thaum muaj kev sib deev. Cov txiv neej thiab poj niam chromosomes cais thiab muab faib mus rau hauv ib tiam zuj zus. Muaj ob theem tseem ceeb ntawm meiosis uas yog meiosis I thiab meiosis II. Zoo ib yam li mitosis, meiosis kuj muaj cov theem xws li prophase, metaphase, anaphase, thiab telophase. Cov chromosomes tau txais los ntawm ob lub hlwb gamete sib txawv; poj niam ov thiab txiv neej phev. Yog li ntawd, thaum lub sij hawm meiosis txheej txheem, cov homologous chromosomes hla dhau. Thaum lub sij hawm meiotic prophase, bivalents yog tsim thiab cov noob caj noob ces sib xyaw ntawm cov ntsiab lus hu ua chiasma. Bivalent los yog tetrad yog ib lub koom haum ntawm homologous chromosomes tsim thaum lub sij hawm prophase I ntawm meiosis. Chiasma yog cov neeg sib cuag taw qhia qhov twg rau homologous chromosomes tsim kev sib txuas ntawm lub cev lossis hla. Qhov sib txawv tseem ceeb ntawm bivalent thiab chiasmata hauv meiosis yog nyob ntawm nws cov qauv kev ua haujlwm. Bivalents yog cov koom haum ntawm homologous chromosomes, whereas Chiasmata yog cov junctions uas homologous chromosomes hu thiab DNA hla dhau qhov chaw.
Dab tsi yog Bivalent hauv Meiosis?
Bivalent yog tsim thaum lub sij hawm meiosis txheej txheem ntawm homologous chromosomes. Hauv meiosis, ob pawg chromosomes los ntawm txiv neej thiab poj niam gamete koom nrog. Cov bivalent yog tsim los ua ib qho kev sib koom ntawm txiv neej thiab poj niam homologous chromosomes. Lub bivalent tseem hu ua tetrad. Nyob rau hauv ib txwm cell faib cov xwm txheej, txhua bivalent muaj tsawg kawg yog ib qho crossover cov ntsiab lus hu ua chiasma. Tus naj npawb ntawm chiasma hauv bivalent muab lub tswv yim ntawm tus ntoo khaub lig tshaj qhov ua tau zoo ntawm DNA thaum lub sij hawm meiosis. Kev tsim ntawm bivalent hauv meiosis yog qhov tseem ceeb vim nws tso cai rau kev sib cais ntawm chromosomes thaum lub sij hawm meiosis.
txheej txheem ntawm Bivalent Formation
Kev tsim ntawm bivalent yog txheej txheem nyuaj thiab koom nrog cov kauj ruam hauv qab no.
- Tsim cov synaptonemal complex uas muaj ob homologous chromosomes.
- Kev ua khub ntawm ob homologous chromosomes uas tshwm sim ntawm leptotene thiab pachytene theem ntawm prophase I ntawm meiosis.
- DNA yog pauv ntawm qee cov ntsiab lus hu ua chiasma.
- Ib qho kev sib txuas ntawm lub cev yog tsim nyob rau theem diplotene ntawm prophase I ntawm meiosis.
- Thaum kawg ntawm theem diplotene, ib qho bivalent tsim.
Daim duab 01: Bivalent
Kev tsim ntawm bivalents yuav xyuas kom meej tias cov caj ces muaj nyob rau hauv sib xyaw ntawm gamete hlwb. Thaum tsim cov bivalents, ib tug nro yog tsim thiab txhua chromatid yog rub nyob rau hauv lub opposite kev taw qhia. Qhov no yuav cia cov bivalents npaj nyob rau hauv nruab nrab ntawm lub cell.
Chiasmata hauv Meiosis yog dab tsi?
Chiasma yog xa mus rau qhov chaw ntawm kev sib cuag ntawm ob homologous chromosomes. Frans Alfons Janssens thawj zaug qhia txog lub tswv yim ntawm Chiasma hauv xyoo 1990. Chiasmata yog tsim los ntawm ob tus muam chromatids uas yog ob homologous chromosomes. Chiasmata tseem ceeb hauv DNA crossover thaum meiosis. Ntawm cov ntsiab lus sib txuas no, cov khoom siv caj ces yog sib pauv ntawm leej niam thiab leej txiv chromosomes.
Daim duab 02: Chiasmata
Kev tsim ntawm chiasma hauv bivalents tshwm sim hauv prophase I ntawm meiosis. Chiasmata tsim yog ib qho tsis tshua muaj tshwm sim hauv mitosis. Vim tsis muaj chiasma tsim, chromosomal aberrations yuav tshwm sim. Chiasmata yog tsim los ntawm kev sib cuag cov ntsiab lus uas nyob twj ywm thaum cov bivalents pib sib cais. Lub Chiasmata tau pom thaum lub sijhawm pachytene ntawm prophase I.
Dab tsi zoo sib xws ntawm Bivalent thiab Chiasmata hauv Meiosis?
- Ob leeg yog tsim thaum lub sijhawm prophase I ntawm meiosis.
- Ob leeg ua rau DNA hla dhau thiab tso cai rau kev cais ntawm chromosomes hauv meiosis.
Qhov txawv ntawm Bivalent thiab Chiasmata hauv Meiosis yog dab tsi?
Bivalent vs Chiasmata in Meiosis |
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| Bivalent lossis tetrads yog cov koom haum ntawm homologous chromosomes tsim thaum lub sijhawm prophase I ntawm meiosis. | Chiasmata yog cov ntsiab lus sib cuag uas ob homologous chromosomes tsim kev sib txuas ntawm lub cev. |
Summary – Bivalent vs Chiasmata in Meiosis
Cov txheej txheem ntawm meiosis yog ib qho tseem ceeb los xyuas kom meej lub neej txuas ntxiv. Lub prophase I ntawm meiosis yog ib theem tseem ceeb uas DNA crossover ntawm niam thiab txiv chromosomes tshwm sim. Thaum lub sij hawm prophase I, ob homologous chromosomes tuaj rau hauv kev sib raug zoo tsim cov qauv bivalent hu ua tetrads. Cov non-viv ncaus chromatids ntawm homologous chromosomes hauv bivalents pauv cov khoom siv caj ces ntawm cov ntsiab lus hu ua chiasma. Qhov no tso cai rau kev sib cais ntawm chromosomes thaum lub sij hawm meiosis. Qhov no yog qhov txawv ntawm bivalent thiab chiasmata hauv meiosis.
Download the PDF Version of Bivalent vs Chiasmata in Meiosis
Koj tuaj yeem rub tawm PDF version ntawm kab lus no thiab siv nws rau offline lub hom phiaj raws li daim ntawv ceeb toom. Thov download PDF version ntawm no Qhov txawv Ntawm Bivalent thiab Chiasmata hauv Meiosis
