Qhov sib txawv tseem ceeb ntawm cov hlab ntsha thiab cov hlwb sib koom yog tias cov hlab ntsha yog cov phloem sieve uas ua zaub mov hauv angiosperms whereas, cov hlwb sib koom yog cov hlwb ntawm cov hlab ntsha. Ntxiv mus, cov hlab sieve muaj qhov pores nyob rau hauv cov phab ntsa transverse thaum lub hlwb khub tsis muaj qhov hws.
Phloem yog ib qho ntawm ob hom kab mob vascular. Nws yog cov ntaub so ntswg vascular uas ua zaub mov los ntawm cov khoom photosynthetic mus rau lwm qhov ntawm cov nroj tsuag. Phloem muaj cov hlwb sib txawv. Ntawm lawv, sieve cell thiab sieve tubes yog ob hom sieve ntsiab lus uas nqa cov zaub mov thauj thoob plaws hauv cov nroj tsuag. Sieve hlwb yog tam sim no feem ntau nyob rau hauv seedless vascular nroj tsuag thiab gymnosperms. Txawm li cas los xij, cov hlab sieve tsuas muaj nyob hauv angiosperms xwb. Sieve raj yog txuam nrog cov nyob ua khub hlwb. Ntxiv mus, cov hlab ntsha thiab cov hlwb ua ke yog qhov tshwj xeeb rau angiosperms.
Sieve Tubes yog dab tsi?
Sieve tubes yog cov khoom sieve muaj nyob hauv angiosperms. Lawv yog cov elongated loj hlwb uas muaj pores nyob rau hauv lawv transverse phab ntsa. Ntxiv mus, nyob rau theem ntawm cov tub ntxhais hluas, sieve raj muaj ib tug nucleus. Tab sis nrog kev loj hlob, lub nucleus disappears ntawm lub sieve tube hlwb. Lawv muaj ob peb tus lej ntawm mitochondria. Txawm li cas los xij, lawv tsis muaj ribosomes, tsis zoo li cov hlwb ua ke.
Daim duab 01: Sieve Tubes
Sieve tube hlwb yeej ib txwm cuam tshuam nrog cov hlwb ua ke kom muaj kev thauj mus los ntawm cov zaub mov zoo. Sieve hlwb tshwm sim nyob rau hauv kawg zam thiab ua ib tug ntev raj los pab txhawb lub conduction. Tsis tas li ntawd, sieve tube hlwb txuas nrog ib leeg los ntawm plasmodesmata. Piv nrog rau cov hlwb ua ke, cov hlab ntsha muaj cov metabolic tsawg.
Cov Kab Mob Sib Nqus yog dab tsi?
Cov hlwb yog cov hlwb elongated txuam nrog sieve tube ntsiab ntawm angiosperms. Cov hlwb no muaj ntau ntawm mitochondria thiab ribosomes. Tsis tas li ntawd, lawv muaj cov nucleus thoob plaws hauv lawv lub neej. Yog li, cov kab mob sib koom ua ke no metabolically ua haujlwm zoo heev. Txawm li cas los xij, cov hlwb no yog cov hlwb me me piv rau cov hlab ntsha.
Daim duab 02: Tus khub Cells
Zoo ib yam li cov hlab ntsha, cov hlwb sib koom tsuas muaj nyob hauv angiosperms xwb. Tsis zoo li cov hlab ntsha, cov hlwb sib koom tsis muaj qhov pores hauv lawv cov phab ntsa transverse.
Dab tsi yog qhov zoo sib xws ntawm Sieve Tubes thiab Companion Cells?
- Sieve hlab thiab cov hlwb ua ke yog tshwj xeeb rau angiosperms.
- Ob leeg yog phloem ntsiab.
- Tseem, lawv yog cov muaj sia nyob.
- Ob leeg koom nrog hauv kev ua zaub mov (sucrose) los ntawm cov khoom siv photosynthetic mus rau lwm qhov ntawm cov nroj tsuag.
- Tsis tas li ntawd, lawv yog cov hlwb elongated.
- Dhau li ntawd, ob hom hlwb muaj mitochondria, ER thiab cellulose cell phab ntsa.
- Ntxiv mus, muaj plasmodesmata nruab nrab ntawm lawv.
Dab tsi yog qhov txawv ntawm Sieve Tubes thiab Companion Cells?
Sieve tubes yog phloem sieve ntsiab lus uas ua zaub mov hauv angiosperms. Txawm li cas los xij, cov kab mob sib luag yog cov kab mob sib txuas ntawm cov hlab ntsha. Yog li, qhov no yog qhov sib txawv tseem ceeb ntawm sieve tubes thiab cov hlwb ua ke. Tsis tas li ntawd, qhov sib txawv tseem ceeb ntawm cov hlab sieve thiab cov hlwb sib koom yog tias cov hlab sieve muaj qhov pores hauv lawv cov phab ntsa transverse cell thaum cov hlwb tsis muaj qhov pores.
Ntxiv mus, cov hlwb ua ke muaj ntau ntawm mitochondria, ribosomes thiab nucleus. Yog li ntawd, qhov sib txawv ntxiv ntawm cov hlab sieve thiab cov hlwb ua ke yog tias cov hlwb sib koom ua ke yog cov metabolically ua haujlwm ntau dua li cov hlab ntsha. Tsis tas li ntawd, feem ntau, sieve hlab yog cov hlwb loj dua li cov hlwb ua ke. Yog li ntawd, peb tuaj yeem xav txog qhov no kuj yog qhov sib txawv ntawm cov hlab ntsha thiab cov hlwb ua ke.
Hauv qab infographic qhia txog qhov sib txawv ntawm cov hlab ntsha thiab cov hlwb ua ke.
Summary – Sieve Tubes vs Companion Cells
Sieve tubes yog cov hlwb uas ua zaub mov hauv angiosperms. Cov hlwb no yog cov hlwb dav dua nyob rau hauv qhov kawg ntawm qhov kawg zam los ua lub raj. Lawv yog txuam nrog me me nucleated hlwb hu ua companion cells. Cov hlwb ua ke yog cov metabolically nquag nquag vim lawv muaj ntau mitochondria thiab ribosomes. Sieve tube hlwb muaj pores los yog sieve daim hlau nyob rau hauv lawv transverse phab ntsa. Tab sis tus khub cell tsis muaj pores. Ob leeg sieve hlab thiab cov hlwb ua ke yog cov hlwb nyob. Lawv tshwj xeeb rau angiosperms. Yog li, qhov no yog cov ntsiab lus ntawm qhov sib txawv ntawm cov hlab sieve thiab cov hlwb ua ke.
