Which of the following are not tropisms?

(i) growing of pollen tube in response to a sugary substance


(ii) folding up of leaves of sensitive plant in response to touch


(iii) winding of tendril around a support in response to touch


(iv) opening up of the leaves of a daisy flower in response to light

Folding up of leaves of sensitive plant in response to touch is known as photonasty which is not a type of tropism. Opening up of the leaves of a daisy flower in response to light is also not an example of tropism.

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