Chemical Coordination in Plants — Biology STD 10 — Question

Phototropism: It is defined as the directional movement of the plant organ in response to the stimulation of light. When a plant organ moves towards light, it is called positive phototropism and when the plant organ moves away from light, it is called negative phototropism.
Most stems, leaves and flower stalks show positive phototropism while most of the roots are negatively phototropic.