Upper vs Lower Epidermis
Nws yog lub stomata uas ua rau qhov sib txawv tseem ceeb ntawm sab sauv thiab sab qis ntawm nplooj. Tsiaj txhu muaj daim tawv nqaij raws li lawv lub npog feem ntau ntawm lub cev. Zoo ib yam li ntawd, cov nroj tsuag muaj ib txheej hu ua epidermis ua lawv lub npog sab nraud. Epidermis pib los ntawm protoderm. Cov txheej txheej sab nraud ntawm apical meristem thiab nplooj primordium hu ua protoderm. Tag nrho cov nroj tsuag lub cev yog them los ntawm no ib leeg cell txheej txheej epidermis. Epidermis tuaj yeem sib txawv rau hauv daim tawv nqaij thiab sab sauv thaum nws tshwm sim rau ntawm nplooj thiab sab saud. Yog li ntawd, sab sauv (adaxial) nto thiab qis (abaxial) nto ntawm nplooj yog hu ua sab sauv thiab qis epidermis feem. Cov kab mob epidermal yog lub cev zoo li lub cev thiab txuas rau ib leeg txhawm rau tsim cov epidermis.
Cov yam ntxwv tshwj xeeb uas nthuav tawm los ntawm cov kab mob epidermis yog; txheej ntawm cutin, guard cells, stomata, thiab trichomes. Ob qho tib si sab sauv thiab sab qis epidermal secrete txheej waxy hu ua cuticle. Cov txheej no pab txo cov evaporation ntawm nplooj. Lub thickness ntawm txheej no txawv raws li hom thiab ib puag ncig tej yam kev mob. Tsis tas li ntawd, nplooj epidermis muaj ntau hom cell tshwj xeeb xws li cov hlwb thiab trichomes. Qhov tshwm sim ntawm cov qauv tshwj xeeb no txawv nyob rau sab sauv thiab sab qis.
Cov neeg zov lub hlwb yog taum los yog ib nrab lunar nyob rau hauv cov duab (cov nyom muaj dumbbell zoo li tus neeg zov lub hlwb). Lub feeb pore puag ncig los ntawm ob lub hlwb tiv thaiv yog hu ua stoma. Tsis zoo li cov kab mob epidermal, cov cell tiv thaiv muaj cov chloroplasts, cov phab ntsa tuab, thiab cov phab ntsa nyias nyias. Lawv tswj qhov qhib thiab kaw ntawm lub stoma. Yog li, transpiration yog tswj los ntawm cov neeg zov lub hlwb. Tsis tas li ntawd, cov hlwb tiv thaiv yog nyob ib puag ncig los ntawm ob lossis ntau lub hlwb uas txawv ntawm cov hlwb li niaj zaus hu ua cov hlwb. Stomata tshwm sim nyob rau hauv epidermis yog varied nyob rau hauv dicots thiab monocots.
Upper Epidermis yog dab tsi?
Upper epidermis muaj lub thoob-zoo li ib lub cell txheej txheej epidermal hlwb. Epidermal hlwb nyob rau hauv ob qho tib si monocots thiab dicots muaj tib lub cev thiab qauv. Feem ntau, cov epidermis sab sauv muaj tsawg tus neeg zov lub hlwb piv rau cov epidermis qis. Qee cov nroj tsuag muaj stomata tsuas yog nyob rau sab sauv epidermis; e.g. dej lilies.
YDab tsi yog Lower Epidermis?
Cov epidermis qis zoo ib yam li cov epidermis sab sauv hauv kev tsim thiab qauv. Txawm li cas los xij, qhov tshwm sim ntawm stomata thiab trichomes yuav txawv raws li hom thiab ib puag ncig. Stomata muaj ntau nyob rau hauv qis epidermis ntawm nplooj dorsiventral. Khoom qab zib nroj tsuag muaj sunken stomata ntawm lawv qis epidermis.
Qhov txawv ntawm Upper thiab Lower Epidermis yog dab tsi?
Ob qho tib si sab sauv thiab sab qis yog muab los ntawm apical thiab nplooj primordium. Ob txheej txheej epidermal muaj ib txheej ntawm lub thoob-zoo li lub hlwb. Epidermal hlwb yog nruj nreem txuas rau ib leeg thiab muab txhua yam muaj zog thiab tiv thaiv los ntawm cov kab mob thiab lwm yam kev mob ib puag ncig. Phab ntsa ntawm nplooj epidermis muaj cov khoom siv waxy hu ua cutin, uas txo cov evaporation ntawm nplooj. Qee cov nroj tsuag muaj cov hlwb uas nyob ib puag ncig cov hlwb ntawm cov epidermis.
Stomatal Density:
• Upper epidermis's stomatal density is less than the low epidermis.
Stomata Cov ntsiab lus:
• Floating nroj tsuag muaj stomata tsuas yog nyob rau sab sauv epidermis.
• submerged nroj tsuag tsis muaj stomata ntawm ob txheej txheej epidermal.
Epidermis ntawm Xerophytic Nroj Tsuag:
• Lub Upper epidermis ntawm xerophytic nroj tsuag tsis muaj stomata.
• Lower epidermis ntawm xerophytic nroj tsuag muaj sunken stomata.
