Kungani izitshalo ziluhlaza?
Izingxenye zesitshalo eziluhlaza, njengamaqabunga, ziluhlaza ngoba ziqukethe i - chlorophyll. I - chlorophyll imunca amandla okukhanya (kodwa kuncane ukukhanya okuluhlaza kunokubomvu noma okuluhlaza okwesibhakabhaka) futhi isiza ukuguqula lawo mandla abe ukudla kwesitshalo njengengxenye ye - photosynthesis.  Impendulo engaqondakali kangako, engelona iqiniso ngokwesayensi, ithi izitshalo zidinga kokubili ukukhanya kwelanga (okumsundu) namanzi (okuluhlaza okwesibhakabhaka) ukuze ziphile futhi okunsundu nokuhlaza okwesibhakabhaka kwenza okuluhlaza.