Ngexesha elithile ebomini bethu, siya kuba sibonile okanye singcamle imbewu yemifuno, enjengemibhobho, i-walnuts, imbewu ye-chia, njl. Uninzi lwabantu luyazi ukuba izityalo zinokuhluma kuzo, Kodwa ngaba babenokukuchaza ngokuthe ngqo ukuba yintoni imbewu?
Ukucacisa nawaphi na amathandabuzo ngokuphathelele iimbewu, siza kucacisa ukuba ziyintoni na, ukubaluleka kwazo, zeziphi iinxalenye ezenziwe ngazo, nendlela ezinokuntshula ngayo. Ukuba unomdla kulo mbandela, ndincoma ukuba uqhubeke ufunda.
Yintoni imbewu kwaye yintoni ukubaluleka kwayo?
Ukuqonda ukubaluleka kwale nxalenye yesityalo, okokuqala siza kuchaza ukuba yintoni imbewu, eyaziwa ngokuba yimbewu, imibhobho, imbewu okanye ootata. Le mizimba iyinxalenye yesiqhamo kwaye ivelisa isityalo esitsha ngokupheleleyo. Ngombulelo kwimbewu, izityalo ze-spermatophyte ziyakwazi ukusabalalisa. Inyaniso encinci enomdla: Eyona mbewu indala eyaziwayo ukuza kuthi ga ngoku ivela kwifosili ebizwa ngokuba yifosili I-Runcaria kwaye yafunyanwa eBelgium.
Kodwa zenziwa njani iimbewu? Kulula kakhulu: Xa i-ovule ye-gymnosperm okanye i-angiosperm ikhula, imbewu iyaveliswa. Iqulethe i-embryo ekwazi ukukhula ibe sisityalo esitsha, ukuba nje iimeko zilungile. Kufuneka kuqatshelwe ukuba imbewu iqulethe indawo yokutya egciniweyo kwaye ihlanganiswe ngohlobo lwesigqubuthelo sokukhusela.
Njengoko besitshilo ngaphambili, imbewu yeyona ndlela kuphela izityalo ze-spermatophyte zinokuzala. Ngaphandle kwabo, inani elibalulekileyo lemifuno aliyi kuba khona. Ngoko ke sinokuthi ukubaluleka kwembewu kubalulekile.
Amalungu embewu
Ekuqaleni, ukutya okugciniweyo luhlobo oluthile lwesihlunu esicolekileyo ekuthiwa i-endosperm. Oku kunikezelwa sisityalo somzali kwaye ngokuqhelekileyo sisityebi kwiprotheni kunye nesitashi okanye ioli. Kwezinye iintlobo zezityalo, i-embryo igcinwe kwi-endosperm. Oku kuya kusetyenziswa yimbewu ukuntshula. Kwelinye icala, kwezinye iintlobo i-endosperm iphelela ekufunxeni i-embryo ngelixa ikhula ngaphakathi kwembewu.
Ngokubhekiselele kwidyasi yembewu, ikhula ukusuka kwiityhubhu ezincinci ezininzi ezijikeleze i-ovule, ebizwa ngokuba amalungu omzimba. Kwezinye izityalo, olu qweqwe lunokuba liqokobhe elibhityileyo xa sele likhulile, elinje ngamandongomane, okanye iqokobhe elikhulu ngakumbi.
Kwimeko ye-angiosperms, imbewu ifumaneka ngaphakathi kwezakhiwo ezinokuthi zome okanye zibe yinyama, kwezinye iimeko zinokuba ngamaleko omabini. Ezi zakhiwo zaziwa ngokuba iziqhamo. Kulwimi lweSpanish, ukutya okuswiti nokunenyama kubizwa ngokuba sisiqhamo. Ngokuchasene noko, imbewu yee-gymnosperms iqala ukukhula "ze" kwiibracts zecones, njengoko kunjalo kwiintyatyambo ezininzi. Ngethuba lokukhula kwabo, bahamba kunye nezikali ezikhuselayo kunye nokunceda ukusasaza.
Inzuzo
Ngokungafaniyo nezilwanyana, kuquka abantu, izityalo zinemida engakumbi xa kufikelelwa ekufuneni iimeko ezilungele ukukhula kwazo nobomi bazo ngokubanzi. Ngenxa yoko, ukuvela kwayo kuye kwahluka kakhulu malunga nokusasazwa. Indlela yembewu yindlela esebenzayo kakhulu yokwandisa abantu bakho kwaye inika uthotho lweenzuzo esiya kuthi sihlomle ngazo apha ngezantsi.
Ukuze imbewu ichume, kufuneka ifike kwindawo efanelekileyo ngexesha lokuntshula kwayo. Iimpawu ezikhuthaza ukuveliswa kwembewu eya kuba sisizukulwana esilandelayo mhlawumbi inxulumene kakhulu neziqhamo kunembewu ngokwazo. Oku kungenxa yokuba owona msebenzi wembewu ngulowo wokwenza umva. Ithetha ntoni le nto? Kulungile yintoni iyakwazi ukunqumamisa ukukhula xa iphawula ukuba iimeko azikho ntle. Ukongeza, inika ixesha elifunekayo ukuze ihlakazeke. Ezi ziinzuzo ezinkulu ezinikezelwa yimbewu.
Ngokweentlobo zezityalo, ifezekisa injongo yayo yokusasaza ngendlela eyahlukileyo. Bangasebenzisa imveliso yembewu eninzi kakhulu njengeqhinga okanye basonge imbewu ngoomaleko obunzima kakhulu obuthamba yingqele yasebusika kunye neemvula, de iqalise ukuntshula.
Indlela yokuntshula imbewu?
Ngoku siyazi ukuba yintoni imbewu, makhe sithethe ngokuntshula kwayo. Kodwa yintoni kanye le? Yinkqubo apho i-embryo iqala ukukhula ibe sisityalo esitsha. Ngokusisiseko yinkqubo kancinane eyenzeka xa imbumba iqala ukudumba ukuze iqhekeze idyasi yembewu. Kule nto, zonke izityalo zifuna uluhlu lwezinto ezisisiseko ukuze ziphuhlise kwaye zifumane amandla aneleyo. Ezi zinto zisisiseko ezifunekayo zihlala zixhomekeke kwiintlobo zezityalo kwaye zezi zilandelayo:
- Amanzi
- Umoya omdaka
- temperatura
- Iityiwa zetyuwa
Kukho iindidi ezimbini zokuntshula: Ukuhluma kwe-Hypogeal kunye nokuhluma kwe-epigeal. Siza kuxoxa ngazo zombini.
Ukuhluma kweHypogeal
Iicotyledons okanye amagqabi okuqala embewu ahlala engcwatywe kwizithole ze-hypogeal. Ekuphela kwendawo ehamba emhlabeni yi-pluule. Kule ntshula, i-hypocotyl imfutshane kakhulu, ingatsho ukuba ayikho. Ngokulandelelana, i-epicotyl iyanda kwaye amaqabunga okuqala okwenyaniso avela. Kule meko, la magqabi okuqala nawo angamalungu okuqala e-photosynthesizing yesityalo. Iimbewu ezenza olu hlobo lokuntshula, umzekelo, ii-cereals, iimbotyi, iiertyisi kunye ne-oki, phakathi kwezinye.
Ukuhluma kwe-epigeal
Kwimeko yezithole ze-epigeal, i-hypocotyl inokukhula okubalulekileyo, okubangela ukuba i-cotyledons ivele emhlabeni. Emva koko, ii-chloroplasts ziyakwazi ukwahlula phakathi kwee-cotyledons, eziphela ngokuziguqula zibe ngamalungu e-photosynthetic. Ekugqibeleni, i-epicotyl iqala ukukhula. Olu hlobo lokuntshula lwenzeka kwimbewu, umzekelo, itswele, iimbotyi, iletisi kunye nemostade emhlophe, phakathi kwabanye.
Ndiyathemba ukuba eli nqaku liwacimile onke amathandabuzo akho malunga nokuba zeziphi iimbewu.