Qhov sib txawv tseem ceeb ntawm meiosis I thiab meiosis II yog tias meiosis I yog thawj lub cell faib ntawm meiosis uas tsim ob lub hlwb haploid los ntawm lub cell diploid thaum meiosis II yog thib ob ntawm tes faib ua kom tiav meiosis los ntawm kev tsim plaub haploid. cells.
Meiosis yog cov txheej txheem cellular thiab biochemical uas txo tus lej chromosome mus rau hauv ib nrab thaum tsim gametes hauv ib lub cev. Thaum kawg, cov txheej txheem no tsim plaub tus ntxhais lub hlwb txhua tus muaj cov chromosomes haploid los ntawm ib lub cell diploid. Meiosis tshwm sim tsuas yog thaum lub sijhawm sib deev ntawm tes tsim hauv spermatogenesis thiab oogenesis. Nws muaj ob qhov kev faib tawm nuclear, uas yog meiosis I thiab meiosis II. Raws li, meiosis I thiab meiosis II muaj plaub ntu hauv txhua qhov. Thaum cov hlwb ua tiav meiosis I, lawv pib mob meiosis II. Ntxiv mus, tsis muaj interphase ntawm ob theem no.
Meiosis kuv yog dab tsi?
Meiosis kuv yog thawj lub cell faib ntawm meiosis. Muaj interphase ua ntej meiosis I. Nws khiav mus ntev dua. Meiosis I muaj plaub theem xws li Prophase I, Metaphase I, Anaphase I, thiab Telophase I. Thaum lub sij hawm prophase I, chromosomes condense thiab khub thiab ua raws li homologous chromosomes. Tom qab ntawd cov homologous chromosome khub, pauv lawv cov khoom siv caj ces ntawm lawv los ntawm kev tsim chiasmata. Ntawm no, kev sib pauv ntawm homologous qhov nruab nrab ntawm homologous chromosomes hu ua hla dhau, thiab nws yog lub luag haujlwm rau kev hloov pauv caj ces.
Daim duab 01: Meiosis I
Tom qab hla dhau, cov khub no txav mus rau lub phaj metaphase thiab teem ib sab ntawm nws thaum lub sijhawm metaphase I. Spindle los ntawm txhua tus ncej pib txuas nrog lub centromeres ntawm chromosomes. Txhua chromosome txuas nrog ib spindle los ntawm ib tug ncej. Yog li ntawd, ob homologous chromosomes txuas nrog spindles los ntawm cov ncej. Thaum anaphase kuv pib, spindles ua luv thiab rub homologous chromosomes sib nrug rau cov ncej. Ib zaug, cov chromosomes ncav cuag ob tus ncej ntawm cov hlwb, telophase kuv pib los ntawm kev tsim cov kab mob hauv lub cev thiab kaw cov chromosomes. Nyob rau theem no, haploid txheej ntawm chromosomes muaj nyob rau hauv txhua lub nucleus. Tom qab ntawd cov chromosomes condense dua, thiab ob lub hlwb tshwm sim. Ua kom tiav qhov meiosis I.
Meiosis II yog dab tsi?
Meiosis II yog theem thib ob ntawm meiosis, nyob rau hauv qhov kev faib ntev ntawm cov chromatids duplicated thiab ntxiv cell division. Thaum lub sij hawm meiosis II, tus ntxhais hlwb tsim los ntawm meiosis kuv txuas ntxiv faib kom txhua tus ntxhais cell los ntawm meiosis kuv tsim ob gametes. Zoo ib yam li meiosis I, meiosis II kuj muaj plaub ntu uas yog Prophase II, Metaphase II, Anaphase II thiab Telophase II. Cov theem no zoo ib yam li cov theem meiosis I. Meiosis II zoo ib yam li mitotic cell division. Tsis tas li ntawd, meiosis II luv dua meiosis I.
Daim duab 02: Meiosis II
Thaum lub sijhawm prophase II, chromosomes condense thiab nuclear membranes tawg. Chromosomes sib txawv. Tsis tas li ntawd, spindles tsim los ntawm txhua tus ncej. Chromosomes kab ntawm lub phaj metaphase ib tus zuj zus. Thaum lub sij hawm metaphase II, ob spindles; ib tug los ntawm txhua tus ncej txuas nrog lub centromere ntawm txhua chromosome. Tom qab ntawd qhov anaphase II pib. Spindles ua luv. Yog li ntawd, centromeres cais thiab tus muam chromatids cais ntawm ib leeg. Cov muam chromatids raug rub mus rau cov ncej sib txawv. Thaum lub sij hawm telophase II, cov ntaub so ntswg nuclear hloov kho thiab kaw cov haploid pawg ntawm chromosomes tsim plaub lub hlwb haploid. Qhov ntawd yog qhov kawg ntawm meiosis II.
Qhov Zoo sib xws ntawm Meiosis I thiab Meiosis II yog dab tsi?
- Meiosis I thiab II yog qhov loj ntawm nuclear kev faib tawm ntawm meiosis.
- Ob txheej txheem muaj plaub ntu.
- Tsis tas li, txhua tus meiosis tsim cov hlwb haploid.
- Dhau li ntawm, cov txheej txheem no tshwm sim thaum lub sijhawm sib deev ntawm tes.
- Yog li ntawd, lawv tseem ceeb hauv kev sib deev.
Qhov txawv ntawm Meiosis I thiab Meiosis II yog dab tsi?
Meiosis kuv yog thawj theem ntawm gamete ntau lawm thaum meiosis II yog theem thib ob ntawm nws. Yog li, qhov no yog qhov sib txawv tseem ceeb ntawm meiosis I thiab meiosis II. Tsis tas li ntawd, cov theem ntawm meiosis kuv yog Prophase I, Metaphase I, Anaphase I, thiab Telophase I, whereas meiosis II yog Prophase II, Metaphase II, Anaphase II, thiab Telophase II.
Tsis tas li ntawd, kev sib cais ntawm homologous chromosomes hu ua synapsis tsuas yog tshwm sim thaum lub sij hawm meiosis I. Tsis tas li ntawd, kev hla tsuas yog tshwm sim thaum lub sij hawm meiosis I. Yog li, ob lub ntsiab lus no tseem qhia qhov txawv ntawm meiosis I thiab meiosis II. Tsis tas li ntawd, ib qho sib txawv ntxiv ntawm meiosis I thiab meiosis II yog tias meiosis-Kuv pib nrog diploid niam txiv cell thiab xaus nrog ob lub hlwb haploid thaum meiosis II pib nrog ob lub hlwb haploid thiab xaus nrog plaub haploid hlwb.
Ntxiv mus, meiosis kuv cais homologous chromosomes thaum meiosis II cais tus muam chromatids. Yog li, qhov no kuj yog qhov sib txawv ntawm meiosis I thiab meiosis II. Qhov tseem ceeb tshaj plaws, genetic recombination tshwm sim hauv meiosis I thaum nws tsis tshwm sim hauv meiosis II. Yog li, qhov no yog qhov sib txawv tseem ceeb ntawm meiosis I thiab meiosis II.
Hauv qab infographic ntawm qhov sib txawv ntawm meiosis I thiab meiosis II summarizes cov sib txawv nrog ntau qhov tseeb.
Summary – Meiosis I vs Meiosis II
Meiosis yog ib qho ntawm ob lub cell loj. Nws tshwm sim ntawm ob theem loj; meiosis I thiab meiosis II. Txhua tus meiosis muaj plaub ntu. Meiosis I tsim ob lub hlwb haploid thaum meiosis II tsim plaub lub hlwb haploid. Tsis tas li ntawd, hauv meiosis I, hla ntawm homologous chromosomes tshwm sim thiab nws ua rau muaj kev hloov pauv caj ces. Tab sis, hauv meiosis II, kev hla dhau thiab kev hloov caj ces tsis tshwm sim. Tsis tas li ntawd, meiosis I yog qhov sib faib heterotypic thaum meiosis II yog homotypic faib. Yog li, qhov no qhia txog qhov sib txawv ntawm meiosis I thiab meiosis II.
