Video: Dab tsi theem DNA condense rau hauv chromosomes?
2024 Tus sau: Miles Stephen | [email protected]. Kawg hloov kho: 2023-12-15 23:36
Thaum prophase , lub nucleus ploj, spindle fibers daim ntawv, thiab DNA condenses rau hauv chromosomes (tus muam chromatids). Thaum lub sij hawm metaphase, tus viv ncaus chromatids ua raws li qhov sib npaug ntawm lub cell los ntawm kev txuas lawv cov centromeres rau cov spindle fibers.
Yog li ntawd, DNA condensed nyob rau theem twg?
Interphase tuaj yeem faib ua peb lub sijhawm: G1, S, thiab G2. G1 thiab G2 yog lub sijhawm uas cov txheej txheem ntawm tes txuas ntxiv mus li qub, thaum lub sijhawm S yog thaum DNA rov ua dua. Thaum lub sij hawm ntau ntawm mitosis, DNA yog qhwv thiab condensed rau hauv chromosomes (daim duab).
Ib yam li ntawd, DNA condensed li cas los tsim chromosomes? Qhov no DNA -protein complex yog hu ua chromatin, nyob rau hauv qhov loj ntawm cov protein thiab nucleic acid yog ze li ntawm sib npaug. Hauv cov hlwb, chromatin feem ntau folds rau hauv cov yam ntxwv tsim hu ua chromosomes . Chromatin condensation pib thaum prophase (2) thiab chromosomes ua pom.
Tsis tas li ntawd, nyob rau theem twg hauv meiosis yog DNA condensed rau hauv chromosomes?
prophase
Nyob rau theem twg DNA nyuaj tshaj plaws pom?
prophase theem
Pom zoo:
S sawv rau dab tsi thiab dab tsi tshwm sim hauv theem no?
S theem sawv rau 'Synthesis'. Qhov no yog theem thaum DNA replication tshwm sim. The G2 stage stands for 'GAP 2'
Dab tsi ntawm chromosomes ua cov spindle fibers txuas rau txhawm rau txav cov chromosomes ncig?
Nws thiaj li, cov microtubules txuas los ntawm centrioles ntawm cov ncej ntawm lub xov tooj ntawm tes txuas mus rau txhua lub centromere thiab txhim kho mus rau hauv spindle fibers. Los ntawm kev loj hlob ntawm ib kawg thiab shrinking rau lwm yam, spindle fibers dlhos cov chromosomes raws nruab nrab ntawm lub cell nucleus, kwv yees li equidistant los ntawm spindle ncej
Ob qhov tseem ceeb ntawm lub voj voog ntawm tes yog dab tsi thiab dab tsi tshwm sim rau lub cell hauv txhua theem?
Muaj ob theem tseem ceeb hauv lub voj voog ntawm tes. Thawj theem yog interphase thaum lub cell loj hlob thiab replicates nws DNA. Qhov thib ob yog theem mitotic (M-Phase) thaum lub sijhawm cell faib thiab hloov ib daim qauv ntawm nws cov DNA mus rau ob lub hlwb zoo tib yam
Dab tsi yog 2 qhov tseem ceeb ntawm lub voj voog ntawm tes thiab dab tsi tshwm sim rau lub cell hauv txhua theem?
Cov xwm txheej no tuaj yeem muab faib ua ob qhov tseem ceeb: interphase (hauv nruab nrab ntawm kev sib faib theem ua pawg G1 theem, S theem, G2 theem), thaum lub xov tooj ntawm tes tsim thiab ua nrog nws cov haujlwm metabolic; mitotic theem (M mitosis), thaum lub sij hawm lub cell yog replicating nws tus kheej
Dab tsi yog qhov voltage ntawm ob theem hauv 3 theem khoom?
Voltage ntawm ob theem hu ua Kab voltage. Kab voltage = 1.73 * Phase voltage. Hluav taws xob hluav taws xob nruab nrab ntawm ib theem 'nyob' thiab 'tsis nruab nrab' hauv peb theem kev faib tawm yog 220 V