Question

How does phototropism occur in plants?

Answer 1

The movement of plant or other organism in response to light is called as phototropism. The movement can be either towards the light or away from it. Stem grows in direction of the sunlight (positively phototropic) and roots grows away from it (negatively phototropic). The growth is controlled by plant hormone, auxin. The growth of the side of the shoot is stimulated by the concentration of auxin. Bending of the stem is caused by the unequal growth on the two sides of the shoot. Phototropic movement is generally caused by the increased auxin on the dark side and lesser auxin on the illuminated side.