Qhov sib txawv tseem ceeb ntawm chromatin thiab chromosomes yog tias chromatin yog untangled thiab unfolded DNA uas tshwm sim raws li ib tug complex ntawm DNA thiab histone proteins thaum chromosomes muaj lub siab tshaj plaws condensed qauv ntawm DNA ob helix rau kev sib cais ntawm cov khoom siv caj ces. nruab nrab ntawm cov ntxhais.
Chromatin thiab chromosome yog ob pawg ntawm cov qauv ntawm ob lub helix ntawm DNA uas muaj nyob rau hauv ntau theem ntawm cov cell. Nws yog ib qho tseem ceeb kom ntim tag nrho DNA uas khaws cov ntaub ntawv keeb kwm ntawm lub xov tooj ntawm tes rau hauv eukaryotic nucleus rau lub neej. Yog li ntawd, chromatin yog ib hom kev ntim DNA hauv lub cell. Ntawm qhov tod tes, chromosomes yog cov qauv tseem ceeb tshaj plaws nyob rau hauv lub cell thaum lub sij hawm faib cell, thiab lawv muaj cov genetic khoom nyob rau hauv daim ntawv ntawm DNA. Qhov no yog vim lawv muaj lub luag haujlwm rau kev xa cov ntaub ntawv keeb kwm yav dhau los ntawm ib tiam mus rau lwm tus. Muaj ob hom chromosomes li autosomes thiab kev sib deev chromosomes. Kev sib deev chromosomes yog qhov tseem ceeb hauv kev txiav txim siab poj niam txiv neej thaum autosomes txiav txim siab lwm yam yam ntxwv. Feem ntau, chromosomes tshwm sim thaum metaphase ntawm cellular faib.
Chromatin yog dab tsi?
Chromatin yog ib qho nyuaj ntawm DNA thiab histone proteins. Feem ntau, chromatin muaj qhov sib npaug ntawm DNA thiab cov proteins. Chromatin zoo li nyias, ntev xov zoo li cov qauv. Lub luag haujlwm tseem ceeb ntawm chromatin yog lub pob yooj yim ntawm cov ntaub ntawv caj ces ntawm lub xovtooj mus rau hauv eukaryotic nucleus rau lub neej. Sib nrug los ntawm kev ntim khoom, chromatin kuj tso cai rau DNA replication los ntawm kev tswj cov noob qhia. Ntxiv mus, nws tiv thaiv DNA puas.
Daim duab 02: Chromatin
Nucleosomes yog cov chav hauv paus ntawm chromatin. Cov no yog cov ntsiab lus tseem ceeb thiab cov txuas DNA txuas nrog cov khoom no. Tsis tas li ntawd, cov khoom tseem ceeb tsim los ntawm kev qhwv 150-200 ntev DNA strands nyob ib ncig ntawm cov tub ntxhais ntawm histone proteins. Txhua nucleosome core particle muaj yim histone proteins.
Tsis tas li ntawd, chromatin tshwm sim thaum lub sij hawm interphase ntawm lub voj voog ntawm tes. Nws muaj ob hom: heterochromatin nrog cov DNA tsis ua haujlwm los muab cov qauv kev txhawb nqa rau lub genome, thiab euchromatin nrog cov genetic nthuav tawm hauv genome.
YChromosomes yog dab tsi?
Ib chromosome yog lub siab tshaj plaws condensed qauv ntawm DNA ob helix txuam nrog histone proteins. Hauv qee cov genomes, lawv muaj ntau dua li cov chromosomes. Li no, peb hu cov ntawv luam ntawm tib chromosome homologous chromosomes. Hauv tib neeg lub cev, 46 chromosomes muaj nyob rau hauv genome hauv 23 khub ntawm homologous chromosomes nrog rau ob chromosomes deev.
Txhua tus chromosome muaj centromeres, telomeres, thiab keeb kwm ntawm kev rov ua dua tshiab sib nrug ntawm cov noob. Qhov pib ntawm DNA replication tshwm sim ntawm lub hauv paus chiv keeb ntawm no replication. Ib zaug replicated, chromosomes muaj ob tug muam chromatids tuav ua ke los ntawm ib tug centromere. Peb hu ua caj npab ntev ntawm chromosome q caj npab, thiab caj npab luv yog p caj npab.
Daim duab 02: Chromosome
Raws li hom centromere, muaj plaub hom chromosomes. Lawv yog telocentric, acrocentric, submetacentric thiab metacentric chromosomes. Tsis tas li ntawd, thaum lub sijhawm kawm ntawm chromosomes, kev faib tawm nuclear raug ntes ntawm metaphase vim tias chromosomes pom zoo nyob rau theem no.
Dab tsi yog qhov zoo sib xws ntawm Chromatin thiab Chromosome?
- Ob leeg chromatin thiab chromosome muaj DNA.
- Peb feem ntau koom nrog ob qho no nrog cov proteins histone.
- Ntxiv mus, ob qho tib si muaj cov ntaub ntawv caj ces ntawm lub xovtooj.
Qhov txawv ntawm Chromatin thiab Chromosomes yog dab tsi?
Chromatin thiab chromosome yog ob hom DNA kev npaj hauv ib lub cell. Chromatin yog untangled thiab unfolded DNA uas tshwm sim raws li ib tug complex ntawm DNA thiab histone proteins thaum chromosomes muaj lub siab tshaj plaws condensed qauv ntawm DNA ob helix. Qhov no yog qhov sib txawv tseem ceeb ntawm chromatin thiab chromosomes. Tsis tas li ntawd, chromatins pom thaum lub sij hawm interphase ntawm lub voj voog ntawm tes thaum chromosomes pom thaum lub sij hawm metaphase ntawm lub voj voog ntawm tes. Yog li, qhov no yog lwm qhov sib txawv ntawm chromatin thiab chromosomes. Lwm qhov sib txawv ntawm chromatin thiab chromosomes yog lawv cov qauv. Chromatins yog nyias, ntev, uncoiled qauv thaum chromosomes yog tuab thiab compact ribbon zoo li cov qauv.
Cov lus qhia hauv qab no qhia txog qhov sib txawv ntawm chromatin thiab chromosomes.
Summary – Chromatin vs Chromosome
Chromatin thiab chromosome yog ob hom DNA uas muaj nyob hauv ntau theem ntawm tes. DNA, RNA, thiab histone proteins yog cov khoom tsim ntawm chromatin. Ob hom chromatin yog euchromatin thiab heterochromatin. Ntawm qhov tod tes, ib chromosome yog lub siab tshaj plaws condensed qauv ntawm DNA ob helix tam sim no nyob rau hauv lub nucleus. Txhua chromosome muaj centromeres, telomeres thiab keeb kwm ntawm kev sib txuas ntawm cov noob. Chromatins yog condensed 50 npaug tshaj li qhov qub DNA ob helix thaum chromosomes yog condensed 10,000 npaug tshaj qhov qub DNA ob helix. Yog li, qhov no yog qhov txawv ntawm chromatin thiab chromosomes.
