Lub qia yog dab tsi? Los ntawm qhov pom ntawm biology, qhov no yog ib feem ntawm cov nroj tsuag uas nplooj thiab paj nyob, uas yog ib qho txuas ntxiv ntawm cov hlab ntsha, uas tshwm sim hauv cov hauv paus hniav. Lub luag haujlwm tseem ceeb ntawm qia yog nqa dej thiab cov zaub mov tseem ceeb ntawm cov av mus rau nplooj thiab lwm qhov chaw ntawm cov nroj tsuag. Ntsuab stems kuj muaj lub luag haujlwm rau kev noj haus thiab koom nrog hauv photosynthesis.
qia: nws cov qauv thiab lub ntsiab lus
Cov ntaub so ntswg kawg ntawm lub qia, muaj peev xwm ntawm cell faib thiab ua rau nws elongate, hu ua apical meristems. Cov khaubncaws sab nraud povtseg ntawm qia muaj xws li cov epidermis, ib txheej txheej ntawm cov hlwb coated nrog ib qho tshwj xeeb cog ciab uas muab kev tiv thaiv los ntawm ib puag ncig sab nraud. Cov ntaub so ntswg tseem ceeb khi cov epidermis thiab phloems sab hauv, uas yog lub luag haujlwm rau kev faib cov khoom photosynthesis thoob plaws hauv cov nroj tsuag. Xylem cov ntaub so ntswg faib dej thiab cov zaub mov los ntawm cov hauv paus hniav mus rau sab saum toj, yog li muab kev txhawb nqa hauv cov nroj tsuag. Cov ntaub so ntswg cambium yog ib txheej ntawm kev faib cov ntaub so ntswg, lawv txoj kev loj hlob tso cai rau lub cev kom loj hlob hauv qhov dav. Tus nqi ntawm qia dag, ua ntej ntawm tag nrho cov, muab cov khoom tseem ceeb ntawm tag nrho cov nroj tsuag. Yog nws puas lawmlos yog nruj nreem qhwv, ces dhau sij hawm, cov ntaub so ntswg, deprived ntawm kev noj haus, pib maj mam qhuav tawm. Ua tiav kev tuag tshwm sim nrog kev tuag ntawm lub hauv paus system. Cov qia seem kuj suav nrog cov pith, uas nyob rau hauv cov ntoo ntoo qub tau sau nrog cov tawv xylem ntawm woody fibers thiab siv rau kev txheeb xyuas cov nroj tsuag. Nws tuaj yeem yog khoom lossis hollow. Nws seem tuaj yeem yog puag ncig, daim duab peb sab lossis lub hnub qub.
Tus yam ntxwv sab nraud
Lub qia yog dab tsi thiab nws zoo li cas? Sab saum toj ntawm qia yog nws lub ntsiab lus ntawm kev loj hlob. Cov receptors nyob rau ntawd tuaj yeem nthuav tawm nyob rau hauv daim ntawv ntawm cov nplooj ntoo vegetative buds thiab cov noob qoob loo. Nyob rau hauv ntau cov nroj tsuag, ib tug tshwj xeeb apical hormone, auxin, inhibits kev loj hlob ntawm lateral buds, li no orienting cov nroj tsuag upwards es sideways. Yog hais tias lub apical bud raug tshem tawm thaum lub sij hawm pruning, ces lub lateral buds loj hlob los ntawm axils ntawm nplooj yuav loj hlob ntau active, thiab qia yuav coj mus rau ib tug bushy zoo. Raws li txoj cai, sab saum toj yog them nrog cov ntawv hloov kho - lub raum nplai, uas ua haujlwm rau kev tiv thaiv. Cov tawv ntoo yog cov ntaub so ntswg tiv thaiv ntawm cov ntoo ntoo thiab loj hlob nrog hnub nyoog.
Vascular system
Cov kab mob vascular yog sawv cev los ntawm kev sib txuas ntawm cov kav dej los ntawm cov dej thiab cov as-ham thauj mus thoob plaws hauv cov nroj tsuag, txuas cov hauv paus hniav, qia thiab nplooj. Tsis yog txhua tus neeg sawv cev ntawm cov nroj tsuag tuaj yeem khav ntawm qhov no, piv txwv li, mosses thiab algae tau txais kev noj haus hauv txoj kev sib txawv. Vascular nroj tsuag muaj xws li flowering thiab cone-bearing nroj tsuag, thiabkuj ferns. Lub kaw lus muaj ob lub ntsiab lus: phloem thiab xylem. Xylem yog lub network ntawm cov kav dej uas thauj cov dej thiab cov zaub mov thoob plaws hauv cov nroj tsuag. Tsis tas li ntawd, nws tseem muab cov kev ua haujlwm thib ob ntawm cov qauv kev txhawb nqa, uas tuaj yeem muab piv rau tus txha nraub qaum, uas yuav pab tswj tau txoj haujlwm upright. Qhov kev ntxhib los mos ntawm qia feem ntau nyob ntawm tus nqi ntawm cov ntaub so ntswg, piv txwv li, nws muaj ntau nyob rau hauv tsob ntoo trunks, nws yog ntau tsawg nyob rau hauv paj.
ntau yam ntawm stems
- Ntaus. Qhov no suav nrog cov ntoo loj hlob vertically nrog cov tub ntxhais loj, nrog rau cov nroj tsuag (roses, grapes, blackberries, raspberries).
- Hloov. Piv txwv li, tulips, lilies, thiab dos muaj tuab, hauv av stems nrog fleshy nplooj. Gladiolus muaj luv luv, thickened underground qia nrog luv, scaly nplooj. Ib tug compressed qia, nrog nplooj loj hlob saum toj thiab hauv qab cov hauv paus hniav thiab paj muaj strawberry, dandelion, African violet.
- Kab rov tav. Piv txwv li, saum toj-hauv av tua ntawm strawberries, iris.
- nce toj stems (honeysuckle, taum).
- hom qia kuj suav nrog tuber, xws li qos yaj ywm.
- Lub cev lub cev, luv thiab flattened, muaj nyob rau hauv begonias, dahlias. Tsis zoo li tubers, uas muaj cov receptors tawg, tuberous stems tsuas muaj nplooj nplooj nyob rau saum.
Stem muaj nuj nqi
1. Nws txhawb cov nplooj, paj thiab txiv hmab txiv ntoo los ntawm kev khi lawv mus rau hauv paus. Hauv cov ntoo thiab cov nroj tsuag, lub ntsiab qia los yog lub cev yog tus cwj pwm los ntawm cov qauv muaj zog.
2. Nws yog cov khoom siv dej, cov as-ham thiab photosynthesis. Nws txoj kev thauj mus los yog tsim los ntawm txoj hauv kev uas ntsug thiab sab txav txav mus rau hauv cov nroj tsuag kab mob ua tau.
3. Lub peev xwm khaws dej thiab cov khoom siv photosynthetic yog qhov tseem ceeb ntawm cov stems ntawm cov nroj tsuag xws li cacti thiab xibtes.
4. Cov tub ntxhais hluas qia ntsuab ua lub luag haujlwm tseem ceeb hauv kev tsim khoom noj los ntawm cov txheej txheem ntawm photosynthesis, tab sis nyob rau hauv qee hom (xws li cacti) qia yog lub ntsiab photosynthetic organ. 5. Nws ua hauj lwm pab raws li ib tug txhais tau tias ntawm asexual reproduction nyob rau hauv ntau hom nroj tsuag, nrog rau cuttings.
Stem qhov
Txhua lub stems ntawm angiosperms, suav nrog cov uas hloov kho, muaj cov nodes, internodes, buds thiab nplooj. Ib lub pob yog ib qho taw tes los ntawm cov nplooj los yog buds loj hlob. Qhov chaw nruab nrab ntawm lawv yog hu ua internode. Lub bud yog lub embryonic qia uas muaj peev xwm loj hlob thiab loj hlob. Nws tuaj yeem loj hlob mus rau hauv nplooj lossis paj. Xws li buds raug xa mus rau raws li nplooj buds, buds thiab mixed buds. Ntau tus ntawm lawv nyob twj ywm rau qee lub sijhawm, tom qab ntawd loj hlob mus rau hauv qhov sib cais lossis yog embedded lawm nyob rau hauv qia cov ntaub so ntswg thiab tsis tshua pom. Ntoo thiab shrubs, ntxiv rau lub ntsiab qia, raws li txoj cai, kuj muaj sab ceg, uas cov ceg me me txuas nrog. Tsuas yognplooj thiab buds, lwm yam qauv tej zaum yuav muaj nyob rau hauv daim ntawv ntawm cov plaub hau, uas yog outgrowths ntawm epidermal hlwb, spines thiab stipules.
Stem dimensions
Thaum teb cov lus nug txog lub qia yog dab tsi, nws tseem ceeb heev uas yuav tau xav txog nws qhov loj me. Nyob rau hauv tag nrho cov nroj tsuag, nws yog feem ntau yog lub saum toj kawg nkaus qhov chaw uas muab cov qauv kev txhawb nqa thiab ua ib tug intermediary thiab conduit ntawm lub hauv paus system thiab nplooj. Cov stems sib txawv me me, xws li ib tug me me vine mus rau 15-meter txoj kab uas hla ntoo!
Meaning
Lub qia yog dab tsi? Peb tuaj yeem hais tias qhov no yog lub hauv paus axis uas tag nrho lwm qhov txuas nrog. Hauv cov nroj tsuag feem ntau, lawv nyob saum npoo av, tab sis hauv qee hom qia tuaj yeem zais hauv av. Nws cov qauv thiab lub ntsiab lus yog inextricably txuas. Vim muaj cov qauv tshwj xeeb, dej thiab cov as-ham raug xa mus rau ob qho tib si nplooj thiab cov hauv paus hniav. Qhov tseem ceeb ntawm cov qia tsis tuaj yeem overestimated; qhov blockage ntawm cov hlab ntsha tseem ceeb no ua rau cov nroj tsuag tuag. Muaj ntau cov ntawv thov kev lag luam, suav nrog kev ua haujlwm ntoo (cov cav ntoo, taws, ntoo). Nws kuj yog ib qho chaw nplua nuj ntawm cellulose rau daim ntawv ua, thiab qee hom stems tuaj yeem yog qhov khoom noj khoom haus. Nws cov fibers ua tiav yog siv rau hauv cov tshuaj, latex, tannins, xim thiab lwm yam. Qee hom stems yog siv rau asexual lossis vegetative propagation ntawm cov nroj tsuag.
Ntau daim ntawv thov ntau
Muaj ntau txhiab hom nroj tsuag uas nws cov stems tseem ceeb heev rau kev ua liaj ua teb, xws li qos yaj ywm. Qab Zib stalks yog lub hauv paus ntawm qab zib. Maple qab zib yog tau los ntawm trunks ntawm maple ntoo. Cov zaub muaj xws li asparagus stalks, xyoob tua, kohlrabi, thiab dej chestnuts. Spicy cinnamon yog cov tawv ntoo. Cov pos hniav arabic yog cov khoom noj ntxiv tau los ntawm cov ntoo acacia. Chicle yog cov khoom xyaw tseem ceeb hauv cov pos hniav thiab los ntawm tsob ntoo chicle. Xyoob yog siv los ua cov ntawv, rooj tog zaum, nkoj, suab paj nruas, nuv ntses, kav dej, thiab txawm lub tsev. Cork yog tau los ntawm bark ntawm cork oak. Cov rattan siv rau cov rooj tog zaum thiab pob tawb yog tsim los ntawm tropical palm stalks. Qhov piv txwv ntxov tshaj plaws ntawm kev siv qhov tseem ceeb ntawm cov nroj tsuag no yog papyrus, nrov hauv Egypt thaum ub. Amber yog fossilized kua txiv los ntawm tsob ntoo trunks, siv rau cov hniav nyiaj hniav kub thiab tej zaum yuav muaj cov seem ntawm cov tsiaj thaum ub. Softwood resins yog siv los ua turpentine thiab rosin.
