How phototropism does occure in plants

1.	How phototropism does occure in plants
Answer» Movement of shoot towards light is called phototropism. This movement is caused due to more growth of cells towards the shaded side of shoot as compared to the side of shoot towards light. More growth of cells is due to secretion of auxin towards the shaded side. The directional movement of a plant in response to light is called phototropism. The shoot responds by bending towards light and roots respond by bending away from light.This happens as follows:(i) When sunlight falls straight on the plant, the auxin hormone synthesised at the tip of the stem spreads uniformly down the stem and due to equal concentration of auxin, stem grows straight.(ii) When sunlight fells on only one side of the plant, the auxin diffuses towards the shady side of shoot. The concentration of auxin stimulates the cells to grow longer. Therefore, the stem appears to bend towards the source of light.\xa0 Plants such as sunflower bend towards the side from which more sunlight is coming.

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