Question

Why is the folding up of the leaves of a sensitive plant on touching with a finger not a tropism ?

Answer 1

•The folding up of the leaves of a sensitive plant on touch with a finger is not a tropism as it is a form of non-directional movement with respect to the stimulus.

•This form of movement is depicted as a nastic movement that is not dependent on the direction of the stimulus
•The non-directional movement of the plant in response to the touch of an object is known as thigmonasty.