Plants bend towards light because

Options

A. they need light for photosynthesis
B. they need light for respiration
C. cells on the shadow side elongate more
D. light attracts them

Answer

**Step-by-Step Solution:**

1. **Understanding Plant Growth and Light**: Plants require light for photosynthesis, which is the process by which they convert light energy into chemical energy. This is essential for their growth and development.

2. **Identifying the Mechanism of Bending**: When light is directed towards one side of the plant, it causes a differential growth response. This phenomenon is known as phototropism.

3. **Role of Auxin**: Auxin is a plant hormone that plays a crucial role in regulating growth. When light shines on a plant, auxin is distributed unevenly, accumulating more on the shaded side of the plant.

4. **Cell Elongation**: The higher concentration of auxin on the shaded side stimulates those cells to elongate more than the cells on the light-exposed side. This differential growth causes the plant to bend towards the light source.

5. **Conclusion**: Therefore, the correct answer to the question "Plants bend towards light because" is that cells in the shadow (the shaded side) start elongating more due to the higher concentration of auxin.

**Final Answer**: Plants bend towards light because cells in the shadow start elongating more (Option C).

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