Kungenzeka wake wezwa ngezihloko ezihlobene nezitshalo ezivela ku- tropism kanye nastia. Angamagama angajwayelekile futhi angokwesayensi kuphela, kepha asetshenziswa kakhulu emkhakheni we-biology kanye ne-botany.
Impela uma ufunda lawa magama, ususondele ekwazini umhlaba wezitshalo futhi uwaqonde kangcono. Ngabe uyafuna ukwazi ukuthi la magama amabili akhuluma ngani?
Tropism
I-tropism ukufuduka okwenziwa izitshalo (noma kwesinye isikhathi izitho ezithile zayo) ukuphendula ukugqugquzela kwangaphandle. Ngoba kunezinhlobo ezahlukahlukene zokuhamba nokunyakazisa indawo, kunezinhlobo eziningana zetropism, futhi kuya ngohlobo lwesikhuthazo esiphendula kulo.
Isibonelo sokuqala kulapho umfutho ophendula izitshalo uvela emandleni adonsela phansi eMhlabeni nokushesha kwawo. Ubizwa ngokuthi yi-gravitropism futhi uqukethe ukukhula kwezimpande zibheke emhlabathini ngenkathi iziqu zikhula phezulu zize zifike ngaphezulu.
Esinye isibonelo i-phototropism lapho izitshalo zisabela khona ekukhanyeni futhi zivumela ukuthuthukiswa kwe-photosynthesis. Okugqame kakhulu yi-heliotropism esekwe ekuhambeni kwesitshalo ngokuya kwelanga. Sithola ubhekilanga abakwazi ukuya elangeni ukukhuphula izinga le-photosynthesis futhi basebenze kahle.
Kukhona ezinye izinhlobo zama-tropism ahlukene, njenge-chemotropism, ekwazi ukuxhumanisa izimpendulo zezitshalo nezakhi zamakhemikhali. Isibonelo, kunezitshalo ezikwazi ukuhamba ukuthola izakhi ezithile zamakhemikhali noma, kunalokho, "ukuzibalekela". Siphinde sithole izikhuthazi ezifana nomoya (i-aerotropism) lapho izitshalo ziziqondisa khona ezifundeni ezinomoya ngaphezulu noma emanzini (i-hydrotropism).
I-nastia
I-nastia ibuye ihambisane nokunyakaza kwezitshalo eziphendula ku-stimuli. Manje ahluke kanjani la magama amabili? Umehluko oyisisekelo phakathi kwe-tropism ne-nastia ukuthi ku-tropism, impendulo ku-stimuli yinto eqhubekayo, okungukuthi, benza njalo.. Isibonelo, ku-aerotropism, izitshalo zizohlala zikhula futhi ziziqondise ezindaweni ezinomoya omningi. Kodwa-ke, ku-nastia, impendulo kuzisusa zangaphandle yenzeka kuphela amahora ambalwa noma imizuzu embalwa.
Futhi ku-nastia, ukuqondiswa kwesikhuthazi akukuthinti ukuhamba kwesitshalo. Isibonelo, sinezitshalo ezidla inyama ezikwazi ukuphendula ukugqugquzela okunjengokuthi isinambuzane sihlala eqabungeni, kepha sikwenza umzuzwana nje. Lapho nje iphendula ekuvuseleleni, ibuyela esimweni sayo sokuqala.
Phakathi kwezibonelo zama-nastias sine-thigmonastia, okuwukuhamba kwesitshalo ekuphenduleni okwesikhashana ukuxhumana naso. Kunezitshalo okuthi ngokuzithinta nje zihambe. Le mpendulo ikhombisa ukuthi isitshalo sizwela kakhulu ekuguqukeni kwemvelo.
Sinezinye izitshalo ezihamba ngenxa yomswakama oweqile noma, ngakolunye uhlangothi, ngenxa yokushoda komswakama. Ibizwa ngokuthi i-hydronastia futhi yenzeka kuphela uma kuba nezinguquko kumswakama. Uma kungekho zinguquko, akukho ukunyakaza. Kodwa-ke, ku-hydrotropism isitshalo sihlala sikhula lapho kunamanzi amaningi khona.
Olunye uhlobo lwe-nastia yi-nictinastia, futhi eyaziwa kangcono ngoba ifaka ukuvulwa nokuvalwa kwamaqabunga ezitshalo kuye ngosuku nasebusuku. Noma i-thermonastia emayelana nokunyakaza kuye ngokushisa kwamvelo.
Njengoba ukwazi ukubona, izitshalo nazo ziphendula kwizikhuthazi zangaphandle ezivela emvelweni. Kunezitshalo ezikhula zifuna izimo ezifanele kakhulu zomoya, ukudla, amanzi, njll. Nabanye abakwaziyo ukunyakaza ukuze bazondle, bazivikele noma basebenze ngesikhathi esithile. Ngalokhu usuvele wazi okuthile okwengeziwe ngezitshalo futhi ungasondela kuzo.