Sylem
She stoo kirpey ymmyrkee lossreeyn cuishlagh ee sylem ny xylem. Shen ass Shenn Ghreagish
Fyshoaylleeaght sylem
[reagh | edit source]Ta sylem currit da ymmyrkey ushtey as beaghey meainagh lheieagh jeh ny fraueyn dys rheynnyn elley y lus. T'ee gaanoaghey yn ushtey ta goll er coayl lesh trooid-ghaalaghey as co-haaghey sollysh. Ta sapp sylem jeant magh jeh ushtey as eeaneyn neuorgaanagh, as ny keayrtyn, ta kemmigyn orgaanagh ayn myrgeddin. Cha nel ny stooghyn kirpey sylem baarail bree dy arraghey y sapp; ta ny stooghyn kirpey hene marroo. Ta daa phenomenon lhiggey da'n tapp arraghey:
- Tayrn trooid-ghaalaghey: she gaalaghey ushtey ass killagyn mesophyll eh ard-vun yn arraghey. T'eh cur er millioonyn dy chorranyn çheet rish ayns boallaghyn ny killagyn mesophyll. Myr shen, ta çhionnid eaghtyr cur çhionnid er y 'liughid as tayrn eh cour ny killagyn mesophyll, as ersooyl jeh ny fraueyn.
- Çhionnid fraue: My ta cummys ushtey ny sloo (ny smoo obballagh) ec ny fraueyn na ec y thalloo, foddee ushtey goll stiagh 'sy fraueyn liorish trooid-heeltaght. Son y chooid smoo, shen er y fa dy vel ram lheiagyn 'sy 'raue. Liorish yn ushtey goll stiagh, ta çhionnid ard 'sy fraue, as t'eh seiy yn ushtey seose cour ny duillagyn. Ny keayrtyn, ta'n sapp goll er seiy magh ass ny duillagyn trooid hydathodeyn, as ta bineyn beggey ry-akin orroo: shen bineal.
Ronsaghey-kirpey sylem
[reagh | edit source]Ta sylem ry-akin ayns caghlaaghyn strughtoor rere y lus t'ayn:
- ayns dhossanyn cuishlagh ta gaase ayns lossreeyn nagh vel fuyghagh; ayns lossreeyn fuyghagh, t'ad ry-akin foast ayns ayrnyn oc nagh vel fuyghagh.
- ayns fo-hylem ta jeant ec cambia cuishlagh.
- ayns steil nagh vel rheynnit ayns dhossanyn, rere aght renniee.
Cha nel ad co-harmeshtagh, agh son y chooid smoo cha nel agh bun-sylem ayns dhossan cuishlagh.
She stoo kirpey cramp t'ayn. Ta killagyn sylem goaill stiagh tracheagyn as tracheidjyn dys ymmyrkey ushtey, chammah's killagyn elley, myr sampleyr parenchyma.
Ta feanish ayn dy vel banglaneaght hylem lhiantyn rish Leigh Murray.[1]
Bun-sylem as fo-hylem
[reagh | edit source]T'ad geddyraghey daa horçh dy hylem rere bun.
Ta bun-sylem çheet er sylem ta jeant ass procambium rish aase toshee lossreeyn. T'ee goaill stiagh protosylem as metasylem; ta cuishlinyn as tracheidjyn metasylem ny shlea na adsyn t'ec protosylem.
Ta fo-hylem çheet er sylem ta jeant ass cambium cuishlagh rish aa-aase. Son y chooid smoo, t'a fo-hylem ry-akin ayns Coniferae as Angiospermae, agh t'eh ec kuse dy Gnetophyta, Ginkgophyta as Cycadophyta myrgeddin.
- Coniferae: ta fo-hylem ec dagh ooilley lus bearkanagh, as ta'n strughtoor echey colaik. Ta fo-hylem biljyn bearkanagh goll er creck myr fuygh bog.
- Angiospermae: shimmey dooie angiospermagh t'ayn. Cha nel fo-hylem erbee ec ny monocotyn, agh t'eh ry-akin ayns possanyn elley. Ta fo-hylem ayn ny dyn rere dooie, as ny keayrtyn rere çhymbyllaght aase hene; t'eh ec y derrey villey, agh cha nel ec y billey elley 'sy dooie cheddin. Cha nel strughtooryn fo-hylem ny caghlaaghyn dooie casley rish y cheilley. Ta fo-hylem biljyn angiospermagh goll er creck myr fuygh creoi.
Aafilley sylem
[reagh | edit source]![](https://upload.wikimedia.org/wikipedia/commons/thumb/e/e6/Ficusxylem.jpg/300px-Ficusxylem.jpg)
Ta feanish ayn jeh sylem fossylagh ass yn eash Siluragh, 400 millioon bleeaney er dy henney, as luirg gollrish killagyn sylem unnaneagh ayns claghyn Ordoviciagh s'leaie. Y feanish s'leaie jeh feer sylem, shen tracheidyn as brat scroddagh ec y voalley killag oc. Shen y sorçh ynrican ta ry-akin ayns lossreeyn cuishlagh leah, as t'eh ry-akin foast ayns protosylem. Dy s'anmey, ren ymmodee possanyn aafilley tracheidyn spohttagh, liorish aafilley cochleanagh: ayns lossreeyn t'ayn jiu, cha nel tracheidyn spohttagh çheet rish neayr's ta'n metasylem er nappaghey.
Son y chooid smoo, she tracheidjyn spohttagh ad ny h-ard-chillagyn ymmyrkey. Ta tracheagyn cochianglt myr cuishley liorish tuill; ta'n ushtey gleashaghey liorish gleashaght stoo 'syn aght cheddin as ushtey ayns pioban, cha nel liorish skeaylley trooid yn 'ar-chrackan killag. Er lesh lus-oayllee, ta sylem mastey ny binn scanshoil lhig da haink lesh angiospermae.[2]. Agh cha nee angiospermae ynrican s'oc tracheagyn, as cha nel y lheid ec shiartanse dy henn linneeaghtyn angiospermagh, myr sampleyr, Amborellaceae, Tetracentraceae, Trochodendraceae, as Winteraceae).
Jeeagh er
[reagh | edit source]Imraaghyn
[reagh | edit source]- ↑ McCulloh, Katherine A.; John S. Sperry and Frederick R. Adler (2003). "Water transport in plants obeys Murray's law". Nature. Ym-lioar 421 (6926): 939–942. doi: . PMID 12607000.
- ↑ Carlquist, S.; E.L. Schneider (2002). "The tracheid–vessel element transition in angiosperms involves multiple independent features: cladistic consequences". American Journal of Botany 89. doi: .
Lioaryn
[reagh | edit source]- Campbell, Neil A.; Jane B. Reece (2002). Biology, 6th, Benjamin Cummings. ISBN 978-0805366242.
- Kenrick, Paul; Crane, Peter R. (1997). The Origin and Early Diversification of Land Plants: A Cladistic Study. Washington, D. C.: Smithsonian Institution Press. ISBN 1-56098-730-8.
- Muhammad, A.F.; R. Sattler (1982). "Vessel Structure of Gnetum and the Origin of Angiosperms". American Journal of Botany 69 (6). Botanical Society of America. doi: .
- Melvin T. Tyree; Martin H. Zimmermann (2003). Xylem Structure and the Ascent of Sap, 2nd, Springer. ISBN 3-540-43354-6.
![]() |
She bun ta'n art shoh. Cur rish, son foays y yannoo da Wikipedia. |