The opening of floral buds and the change into a flower is a nastic movement. It is a type of autonomic movement of growth in which the direction of the movement isindependent of the direction of the stimulus. In fact, the response is determined by the structure of the responsive organ and not by the opposite side. Related Theory Paratonic growth movement are movements of curvature brought about by more growth on one side and less growth on the opposite side of plant organ induced by some external stimuli. e.g., roots move away from light and they are called negatively phototropic.