Lub neej voj voog ntawm lub xovtooj ntawm tes yog lub sijhawm ntawm kev muaj nyob ntawm ib chav tsev ntawm cov neeg nyob los ntawm nws qhov tsos los ntawm kev faib mus rau nws tus kheej faib lossis kev tuag. Nws suav nrog txhua qhov kev hloov pauv tsis tu ncua uas cov organelles tau dhau los thaum ua lawv txoj haujlwm.
Nyob ntawm nws lub koom haum thiab kev tshwj xeeb, lub neej ntawm lub xov tooj ntawm tes tuaj yeem kav li 30 feeb lossis 3 hnub. Piv txwv li, thaum lub sij hawm cell fragmentation nyob rau hauv echinoderms, lub neej voj voog lub sij hawm yog 30 feeb, thiab plab hnyuv epidermis nyob rau hauv tib neeg yog los ntawm 12 teev. Kuj tseem muaj cov chav nyob hauv cov neeg nyob uas tsis sib faib, piv txwv li, tsis sib faib, lawv ua lawv lub luag haujlwm thiab tuag - piv txwv li, paj hlwb, striated nqaij fibers. Lub neej voj voog ntawm tes nws tus kheej feem ntau muab faib ua ob lub sijhawm: interphase, lossis lub sijhawm loj hlob, thiab mitosis, lub sijhawm faib. Interphase suav nrog, feem, ob peb theem:
- G1 (post-mitotic) - theem pib ntawm kev loj hlob. Nyob rau theem no, mRNA, proteins thiab lwm yam khoom ntawm tes tau sib sau ua ke.
- S (synthetic) - DNA replication tshwm sim, uas ua rau muaj ob npaug ntawm cov khoom siv caj ces. Thaum kawgtheem, ob zoo tib yam DNA ob helixes yog tsim. Txhua ntawm cov chains ntawm deoxyribonucleic acid muaj ib tug qub helix, thiab lub thib ob - ib tug tshiab, uas tau tsim raws li lub hauv paus ntsiab lus ntawm complementarity.
- G2 (premitotic) - cov txheej txheem kho yog tab tom ua, uas suav nrog kev kho qhov tsis raug ua thaum lub sijhawm DNA synthesis nyob rau theem dhau los. Cov zaub mov thiab lub zog sib sau ua ke, cov proteins thiab RNA txuas ntxiv mus ua ke.
Qhov txuas tseem ceeb hauv kev tsim tawm yog lub voj voog mitotic ntawm lub xov tooj ntawm tes, lossis kev loj hlob, uas tam sim ntawd pib tom qab G2. Nws yog ib txheej txheej txheem uas tshwm sim nyob rau hauv lub elementary structural unit ntawm cov nyob los ntawm ib tug faib mus rau lwm qhov thiab xaus nrog tsim ntawm cov ntxhais hlwb ntawm ib tug tshiab tiam. Mitosis yog hom tseem ceeb ntawm kev faib tawm ntawm somatic (tsis koom nrog kev sib deev kev sib deev) cov chav tsev ntawm cov kab mob nuclear.
Lub neej voj voog ntawm lub xovtooj ntawm tes yog qhov tseem ceeb rau lub cev, ua kom muaj kev khaws cia ntawm tus lej thiab cov duab ntawm chromosomes tus yam ntxwv ntawm txhua hom (karyotype), yog li nws yog ib qho tseem ceeb uas txhua lub sijhawm ntawm kev faib hla tsis muaj kev cuam tshuam. Mitosis muaj 4 theem ua tiav:
- Prophase. Thaum lub sij hawm no, lub cell faib thiab diverges mus rau tus ncej ntawm lub centrioles, uas yog interconnected los ntawm lub division spindle. Thaum kawg ntawm lub sijhawm no, cov nucleoli disintegrate, cov chromosomes thicken thiab shorten, i.e. tshwm sim
- Metaphase. Nucleoprotein cov qauv kab nyob rau hauv txoj kab nruab nrab ntawm lub cell, ib tug metaphase phaj yog tsim. Nws muaj ib tug thawj constriction ntawm chromosomes. Tom qab ntawd txhua tus ntawm lawv faib ua 2 chromatids.
- Anaphase. Nyob rau theem no, tus ntxhais chromosomes txav mus rau cov ncej sib txawv, qhov chaw uas lawv nyias tawm thiab so.
- Telophase. Cov nucleolus thiab nucleus tau rov qab los, thiab cytoplasm faib.
lawv condensation.
Yog li, lub voj voog ntawm tes yog lub sijhawm ntawm lub neej txij thaum yug mus txog rau qhov tuag ntawm ib chav tsev ntawm lub neej.
