Qhov Tseem Ceeb - Apical vs Lateral Meristems
Cia peb xub nkag siab tias meristem yog dab tsi, ua ntej saib qhov sib txawv ntawm apical thiab lateral meristems. Meristem yog cov ntaub so ntswg tshwj xeeb ua los ntawm cov hlwb uas tsis muaj qhov sib txawv thiab muaj peev xwm sib faib tsis tu ncua los tsim cov ntaub so ntswg tshiab. Ib qho ntxiv, cov hlwb no muaj qee cov yam ntxwv dav dav, uas suav nrog lub voos xwmfab uas muaj ntom nti, ib lossis ntau dua cov kab cytoplasm, muaj cov qauv ntawm homogenous, nyias cov phab ntsa ua nce ntawm cellulose, thiab tsis muaj intercellular qhov chaw thiab ergastic teeb meem. Txij li cov hlwb no muaj lub zog ntawm kev faib tawm, lawv cov metabolic tus nqi siab heev piv rau cov hlwb hauv lwm cov ntaub so ntswg. Kev faib tawm ntawm meristems yog ua tiav raws li lawv lub hauv paus chiv keeb, theem kev loj hlob, qauv thiab kev ua haujlwm. Muaj peb hom meristems raws li lawv txoj hauj lwm nyob rau hauv ib tsob nroj, uas yog; apical meristem, intercalary meristem, thiab lateral meristem. Qhov sib txawv tseem ceeb ntawm apical thiab lateral meristem yog, apical meristem pab nyob rau hauv thawj txoj kev loj hlob ntawm cov nroj tsuag whereas lateral meristem pab nyob rau hauv lub thib ob txoj kev loj hlob ntawm ib tsob nroj.
Apical Meristem yog dab tsi?
Apical meristems yog nyob rau ntawm apices ntawm stems, cov hauv paus hniav thiab lawv cov ceg ntoo. Qhov no meristem yog lub luag haujlwm rau txoj kev loj hlob ntsug ntawm cov nroj tsuag raws nws axis. Lub apical meristem yog dome-puab thiab muaj ob ntu; txheej txheej (tunica) thiab puab pawg (corpus). Nws yog tsim los ntawm ib qho me me ntawm cov hlwb thiab tsim cov ntaub so ntswg mus tas li ntawm cov nroj tsuag (thaum loj hlob) nrog rau cov epidermis, xylem, phloem, thiab cov ntaub so ntswg hauv av. Lub hauv paus apical meristem yog them los ntawm ib txheej tiv thaiv ntawm tes hu ua lub hauv paus cap. Cov hlwb ntawm apical meristem muaj tag nrho cov yam ntxwv ntawm meristem. Lub tua apex yog txawv heev ntawm lub hauv paus apex. Cov tua apical meristem muab nce mus rau nplooj primordia (uas npog thiab tiv thaiv tua apical meristem), thiab bud primordia.
Lateral Meristem yog dab tsi?
Lateral meristems muaj cov vascular cambium thiab cork cambium thiab yog lub luag haujlwm rau kev loj hlob theem nrab ntawm cov ntaub so ntswg. Qhov kev loj hlob theem nrab nce lub girth ntawm cov nroj tsuag (kab rov tav kev loj hlob). Lateral meristem pom nyob rau tag nrho qhov ntev ntawm qia thiab hauv paus tsuas yog ntawm apices. Nyob rau hauv ib tug ntoo khaub lig seem ntawm qia los yog hauv paus ntawm ib tug nroj tsuag uas undergoes theem nrab kev loj hlob, lub lateral meristem yuav pom raws li rings.
Qhov txawv ntawm Apical thiab Lateral Meristems yog dab tsi?
Definition of Apical and Lateral Meristem:
Apical meristem: Ib tsob ntoo cov ntaub so ntswg nrog cov hlwb tsis sib txawv pom ntawm qhov kawg ntawm cov tua lossis hauv paus thiab yog lub luag haujlwm rau kev loj hlob thawj zaug.
Lateral meristem: Ib tsob ntoo cov ntaub so ntswg nrog cov hlwb tsis sib xws uas pom raws qhov ntev ntawm cov qia thiab cov hauv paus hniav thiab yog lub luag haujlwm rau kev loj hlob theem nrab.
Features ntawm Apical thiab Lateral Meristem:
Qhov chaw:
Apical meristem: Apical meristems yog nyob rau ntawm apices ntawm stems, cag, thiab lawv cov ceg ntoo.
Lateral meristem: Lateral meristems pom raws tag nrho qhov ntev ntawm qia thiab hauv paus tsuas yog ntawm apices.
Hom Loj:
Apical meristem: Kev loj hlob ntawm thawj zaug tshwm sim ntawm apical meristems.
Lateral meristem: Kev loj hlob thib ob tshwm sim ntawm lateral meristems.
Growth:
Apical meristem: Apical meristem nce qhov ntev ntawm cov nroj tsuag raws nws txoj kab ntsug, Lateral meristem: Lateral meristem nce girth ntawm cov nroj tsuag.
Cov ntsiab lus:
Apical meristem: Apical meristem ua rau muaj cov kab mob primordia thiab bud primordia, tsis zoo li lateral meristem.
Lateral meristem: Lateral meristems muaj cov vascular cambium thiab cork cambium, tsis zoo li apical meristem.
Tissue Types:
Apical meristem: Apical meristem ua rau cov ntaub so ntswg mus tas li xws li epidermis, xylem, phloem, thiab cov ntaub so ntswg hauv av.
Lateral meristem: Lateral meristem ua rau ntoo, sab hauv tawv thiab txheej tawv.
Image Courtesy: "Apical Meristems in Crassula ovata" los ntawm Daniel, levine - Digital Camera.(CC BY-SA 3.0) ntawm Wikipedia "Japanese Maple Bark" los ntawm David Shankbone- Tus kheej ua haujlwm. (CC BY-SA 3.0) via Commons
