A green plants bends towards the source of light when exposed to the light on only one side . Which of the following is the best explanation of the phenomenon ?

Options

A. The apices of the stems are attached by light
B. The plants needs light for photosynthesis
C. Auxin accumulates on the shaded side to induce great cell elongation on that side
D. Ligh reduces length.

Answer

**Step-by-Step Solution:**

1. **Understanding the Phenomenon**: When a green plant is exposed to light from one side, it bends towards the light source. This bending is known as phototropism.

2. **Role of Plant Hormones**: The bending of the plant towards the light is primarily influenced by a plant hormone called auxin. Auxin is responsible for promoting cell elongation in plants.

3. **Unequal Distribution of Auxin**: In the case of unilateral light exposure (light coming from one side), auxin accumulates on the shaded side of the plant. This accumulation causes the cells on that side to elongate more than the cells on the light-exposed side.

4. **Resulting Growth Pattern**: The unequal elongation of cells leads to a curvature of the plant towards the light source. This means that the side of the plant that is shaded grows longer than the side that is exposed to light.

5. **Conclusion**: Therefore, the best explanation for why a green plant bends towards the light when exposed to it on only one side is that auxin accumulates on the shaded side, inducing greater cell elongation on that side. This phenomenon is known as phototropic curvature.

**Final Answer**: The best explanation for the bending of the plant towards the light source is that auxin accumulates on the shaded side to induce greater cell elongation on that side.

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