Ib qho ntawm cov ntsiab lus ntawm cov kev xav paub zoo ntawm cov qauv cellular yog cov lus hais txog qhov pom ntawm cov hlwb tshiab los ntawm qhov qub, uas yog, niam txiv. Tab sis qhov no tuaj yeem tshwm sim hauv ob txoj hauv kev. Ib tug ntawm lawv yog mitosis. Nws yog ib qho tseem ceeb rau cov txheej txheem ntawm kev yug me nyuam ntawm lawv tus kheej hom. Dab tsi hlwb raug tsim los ntawm mitosis, lawv tus lej thiab cov yam ntxwv ntawm cov txheej txheem yog dab tsi - tag nrho cov no yuav tau tham txog hauv peb tsab xov xwm.
Cell cycle
Ib lub xovtooj ntawm txhua yam kabmob muaj peev xwm muaj nyob rau lub sijhawm ntawm nws ob qhov kev faib lossis txij thaum pib ntawm txoj haujlwm no mus txog rau lub sijhawm tuag. Lub sijhawm no yog lub voj voog ntawm tes. Nws suav nrog cov theem ntawm cov txheej txheem faib nws tus kheej thiab qee lub sijhawm ntawm lawv, uas yog hu ua interphase. Thaum lub sij hawm no, cell loj hlob thiab tsim cov as-ham.
Tab sis ib qho ntawm feem ntauCov ntsiab lus tseem ceeb yog cov txheej txheem ntawm duplication ntawm DNA macromolecules. Tag nrho cov ntaub ntawv keeb kwm ntawm lub xovtooj ntawm tes yog encrypted nyob ntawd.
Kev faib cell tshwm sim li cas
Meiosis rov tsim cov phev thiab qe. Lub ntsiab ntawm cov txheej txheem no yog tsim ntawm plaub haploid gametes los ntawm niam cell nrog ob txheej chromosomes. Vim li no, nws tseem hu ua kev txo qis. Qhov no tseem ceeb heev, vim hais tias thaum lub sij hawm fertilization, ib tug tshiab kab mob tshwm sim los ntawm cov kab mob hlwb, muaj ib nrab ntawm cov ntaub ntawv keeb kwm los ntawm leej niam thiab leej txiv. Thiab qhov no yuav ua tau tsuas yog tias gametes haploid.
Cov hlwb twg tsim los ntawm mitosis? Cov lus teb yog yooj yim: diploid, uas yog, nrog ob chromosome teeb. Cov txheej txheem no tseem ceeb heev. Qhov no yog vim qhov tshwm sim ntawm mitosis, cov hlwb raug tsim uas yog ib daim qauv ntawm leej niam. Lawv txhua tus somatic.
Mitosis theem
Cov txheej txheem ntawm kev tsim cov hlwb tshiab somatic suav nrog ntau theem. Lawv lub sijhawm tag nrho, nyob ntawm seb hom kab mob, thaj tsam li ntawm ob peb feeb mus rau ob peb teev.
theem pib hu ua prophase. Lub sijhawm no, cov xov chromatin yog compacted, lub nucleoli raug txo, thiab fission spindle yog tsim. Lub plhaub ntawm lub nucleus disintegrates, raws li qhov tshwm sim ntawm cov chromosomes nkag mus rau cytoplasm.
theem thib ob hu ua metaphase. Nws lub ntsiab lus yog nyob rau hauv kev tsim kho ntawm chromosomes nyob rau hauv ib lub dav hlauthiab txuas spindle threads rau lawv. Qhov no yog ua raws li anaphase, uas yog qhov luv tshaj theem. Raws li qhov tshwm sim ntawm mitosis, tag nrho cov ntxhais cov hlwb raug tsim. Cov txheej txheem no xaus rau ntawm theem telophase. Hauv qhov no, chromosomes yog despiralized. Lawv yuav luag tsis pom nyob rau hauv lub teeb tsom iav. Tsis tas li ntawd, lub plhaub ntawm lub nucleus pib tsim nyob ze ntawm cov chromatids, thiab kev faib spindle maj mam ploj mus.
pes tsawg lub hlwb tsim los ntawm mitosis
Mitosis raws li ib txoj hauv kev faib cov hlwb eukaryotic yog qhov tshwm sim ntau tshaj plaws. Kev kho dua ntawm qhov ploj lossis puas ntawm lub cev tshwm sim los ntawm cov txheej txheem no. Raws li qhov tshwm sim ntawm mitosis, ob tug ntxhais cell yog tsim los ntawm ib tug niam txiv cell. Nyob rau tib lub sijhawm, vim muaj qhov sib npaug ntawm DNA molecule nyob rau hauv lub interphase ntawm lub voj voog ntawm tes, lub diploid chromosome tau khaws cia.
Mitosis yog lub hauv paus ntawm txhua hom kev yug me nyuam: vegetative - nyob rau hauv cov nroj tsuag, cell faib nyob rau hauv ob - nyob rau hauv protozoa, ntau cleavage - nyob rau hauv malarial plasmodium, sporulation - nyob rau hauv fungi thiab ferns, budding - nyob rau hauv coelenterates.
Kev lom neeg tseem ceeb ntawm mitosis
Raws li qhov tshwm sim ntawm mitosis, cov hlwb uas muaj tib lub chromosome teem raws li niam cov hlwb raug tsim. Yog li ntawd, cov txheej txheem ntawm kev hloov pauv ntawm cov ntaub ntawv caj ces yog ua kom ntseeg tau, txawm tias muaj pes tsawg qhov kev faib tawm mus tas li. Thaum lub sij hawm tus txheej txheem no, ob qho tib si tus naj npawb ntawm chromosomes thiab qhov sib lawv liag ntawm nucleotides hauv DNA molecules nyob tas li.
YogYog li, raws li qhov tshwm sim ntawm mitosis, ob lub cell yog tsim los ntawm ib lub xovtooj ntawm tes, uas tau luam tag nrho cov qub. Qhov no ua kom muaj kev ruaj ntseg ntawm karyotypes thiab yog qhov yuav tsum tau ua ua ntej rau kev muaj sia nyob ntawm tag nrho cov kab mob nyob thoob plaws lub sijhawm tag nrho ntawm lawv tus kheej thiab kev txhim kho keeb kwm.
