Isakhiwo kanye Nomsebenzi Wezicubu Ze-Xylem Neze-Phloem Ezitshalweni
Isingeniso:
Izitshalo, izisekelo zokuphila kwasemhlabeni, zikwazi ukusinda nokuchuma ezindaweni ezahlukahlukene ngenxa yenethiwekhi eyinkimbinkimbi yezicubu nezinhlelo. Phakathi kwalezi, izicubu ze-xylem neze-phloem ziyisisekelo, zidlala indima ebalulekile ekuthuthweni kwamanzi, izakhamzimba, kanye nokudla kuso sonke isitshalo. Lesi sihloko sihlola isakhiwo kanye nomsebenzi wezicubu ze-xylem neze-phloem, sichaza izindima zazo ezibalulekile ku-physiology yezitshalo kanye nempilo iyonke.
Izicubu ze-Xylem:
Isakhiwo se-Xylem:
I-Xylem iyisicubu esikhethekile esizinikele ngokuyinhloko ekuthuthweni kwamanzi nezakhamzimba ezincibilikayo ezivela ezimpandeni ziye ezingxenyeni ezahlukene zesitshalo. Izicubu ze-Xylem zakhiwa izinhlobo eziningana zamaseli: ama-tracheids, izakhi zemithambo yegazi, imicu ye-xylem, kanye ne-xylem parenchyma.
1. Ama-tracheid:
Ama-tracheid amangqamuzana amade anezindonga ezijiyile neziqinile kanye nezinhlangothi ezinciphayo. Axhumene ngemigodi, evumela amanzi ukuthi ahambe eceleni phakathi kwamaseli. Ama-tracheid ayisici esivelele kuma-gymnosperms kanye nezitshalo zemithambo yegazi zasendulo.
2. Izinto Zesitsha:
Izakhi zemikhumbi zimfushane futhi zibanzi kunezingqimba futhi zivumelanisa ukuphela nokuphela ukuze zakhe amashubhu aqhubekayo abizwa ngokuthi imikhumbi. Lezi zakhiwo zisebenza kahle kakhulu ekuqhubeni amanzi futhi zitholakala kakhulu kuma-angiosperms. Izindonga zokugcina zezakhi zemikhumbi zinezimbobo, okuvumela ukugeleza kwamanzi okungavimbeli.
3. Imicu ye-Xylem:
Imicu ye-Xylem iyizingqamuzana ezinde, eziqinile ezihlinzeka ngokusekelwa kwesakhiwo esitshalweni. Nakuba zingabamba iqhaza nasekuthuthweni kwamanzi, indima yazo eyinhloko iwukusebenza ngomshini, okusiza isitshalo ukuthi silondoloze ukuqina kanye nesakhiwo saso.
4. I-Xylem Parenchyma:
Amaseli e-Xylem parenchyma angamaseli aphilayo ahilelekile ekugcinweni kwezakhamzimba kanye nokuthuthwa kwamanzi kanye nezinto ezincibilikayo eceleni. Adlala indima ebalulekile yokusekela ngaphakathi kwezicubu ze-xylem.
Umsebenzi we-Xylem:
Umsebenzi oyinhloko wezicubu ze-xylem ukuhambisa amanzi namaminerali ancibilikile kusuka ezimpandeni kuya ezingxenyeni zasemoyeni zesitshalo. Lokhu kuhamba kwenzeka ngenqubo ebizwa ngokuthi i-transpiration, ehilela ukuhwamuka kwamanzi avela kumaseli e-mesophyll emaqabungeni, okudala ingcindezi engemihle edonsela amanzi phezulu nge-xylem.
I-Xylem iphinde inikeze ukwesekwa kwemishini esitshalweni, ngenxa yokuqina kwamaseli e-xylem. I-Lignin, i-polymer eyinkimbinkimbi yezinto eziphilayo, iqinisa izindonga zamaseli, izenze ziqine futhi zikwazi ukumelana nokucindezeleka okubangelwa ukunyakaza kwamanzi phezulu.
Izicubu ze-Phloem:
Isakhiwo sePhloem:
Ngokuphambene ne-xylem, izicubu ze-phloem zinomthwalo wokuthutha izakhamzimba eziphilayo, ikakhulukazi i-sucrose, ekhiqizwa yi-photosynthesis. Izicubu ze-phloem zakhiwe yizakhi zeshubhu lesihlungo, amaseli ahambisanayo, imicu ye-phloem, kanye ne-phloem parenchyma.
1. Izinto Zeshubhu Lesihlungo:
Izinto zeshubhu lesihlungo ziyizisele eziyinhloko eziqhuba i-phloem. Zinde futhi zivumelanisa ukusuka komunye nomunye ukuze zakhe amashubhu esihlungo. Izindonga zokugcina, ezaziwa ngokuthi amapuleti esihlungo, zimboziwe, okuvumela ukugeleza kahle kwe-phloem sap.
2. Amaseli Ahambisanayo:
Amaseli ahambisanayo ahlobene eduze nezakhi zeshubhu lesihlungo futhi abalulekile ekusebenzeni kwe-phloem. Anama-plasmodesmata amaningi awaxhumanisa nezakhi zeshubhu lesihlungo, okwenza kube lula ukudluliselwa kwezinto. Amaseli ahambisanayo asiza ekulayisheni nasekuthululweni koshukela emashubhu esihlungo, okuqinisekisa ukugcinwa kokugeleza.
3. Imicu ye-Phloem:
Imicu ye-phloem iyiseli le-sclerenchyma elihlinzeka ngokusekelwa kwesakhiwo. Le micu ivame ukuba mide futhi ibe lukhuni, okwengeza amandla ezicutshini ze-phloem.
4. I-Phloem Parenchyma:
Amaseli e-phloem parenchyma ahilelekile ekugcinweni nasekuthuthweni kwezakhamzimba eceleni. Adlala indima yokusekela ngaphakathi kwe-phloem, enikela ekusebenzeni kahle kwezicubu.
Umsebenzi we-Phloem:
Umsebenzi oyinhloko wezicubu ze-phloem ukuthutha izakhamzimba eziphilayo zisuka emaqabunga, lapho zenziwa khona, ziye kwezinye izingxenye zesitshalo lapho zidingeka khona ukuze zikhule, zigcinwe, futhi zisebenzise umzimba. Le nqubo, eyaziwa ngokuthi i-translocation, incike endleleni yokugeleza kwengcindezi. I-Sucrose nezinye izakhamzimba zifakwa ngenkuthalo emapayipini esisefo emaqabungeni, okudala ingcindezi ephezulu ye-osmotic edonsa amanzi emapayipini avela kumaseli azungezile. Lokhu kucindezela kuqhuba ukugeleza kwe-phloem sap ezindaweni ezinengcindezi ephansi, ngokuvamile izindawo zesitshalo ezikhula noma ezigcina izakhamzimba ngenkuthalo.
I-phloem nayo idlala indima ebalulekile ekudluliseni izimpawu kanye nokuxhumana ngaphakathi kwesitshalo. Ithutha ama-molecule ahlukahlukene okudlulisa izimpawu, okuhlanganisa ama-hormone, amaprotheni, kanye nama-RNA, aqondisa ukukhula, intuthuko, kanye nezimpendulo ezithinta imvelo.
Ukuhlanganiswa Kwemisebenzi ye-Xylem ne-Phloem:
Ukusebenza kahle kwezitshalo kuncike emsebenzini ohlangene wezicubu ze-xylem neze-phloem. Amanzi athuthwa yi-xylem abalulekile kwi-photosynthesis, ukuthuthwa kwezakhamzimba, kanye nokugcinwa kwe-cell turgor. Izakhamzimba eziphilayo ezithuthwa yi-phloem zinikeza amandla kanye nezakhi zokwakha ezidingekayo ekukhuleni, ekuzaleni nasekugcinweni.
Izicubu ze-Xylem neze-phloem zihlelwe zaba yizinqwaba zemithambo yegazi ezitshalweni eziningi, okuqinisekisa ukusondelana kwendawo futhi kwenza kube lula ukushintshana kwezinto. Lokhu kuhlanganiswa kusekela ibhalansi ye-metabolic yesitshalo kanye nokuzivumelanisa nezimo zemvelo ezishintshayo.
Isiphetho:
Izicubu ze-xylem neze-phloem zibalulekile ekusindeni nasekukhiqizeni kwezitshalo. I-Xylem iqinisekisa ukuthuthwa kwamanzi namaminerali phezulu, kuyilapho i-phloem isakaza izakhamzimba eziphilayo kuso sonke isitshalo. Zombili izicubu, ngezakhiwo zazo ezikhethekile kanye nemisebenzi ehlelekile, zenza izitshalo zikhule, zizale, futhi ziphendule endaweni ezikuyo. Ukuqonda isakhiwo kanye nomsebenzi wezicubu ze-xylem neze-phloem akugcini nje ngokukhanyisa i-physiology eyinkimbinkimbi yezitshalo kodwa futhi kugcizelela ukuzivumelanisa okumangalisayo kwalezi zinto eziphilayo nokuphila kwasemhlabeni.
