Aerenchyma is helpful to plants by -

Options

A. Providing buoyancy in hydrophytes
B. Absorption in stilt roots
C. Giving mechanical strength to plants
D. Giving flexibility to plants

Answer

**Step-by-Step Text Solution:**

1. **Understanding Aerenchyma**: Aerenchyma is a specialized type of parenchyma tissue found in some plants, particularly those that grow in aquatic or waterlogged environments. It is characterized by large air spaces that facilitate gas exchange.

2. **Function of Aerenchyma**: The primary function of aerenchyma is to provide buoyancy to hydrophytes (water plants). The air-filled spaces allow these plants to float on water, which is essential for their survival and growth.

3. **Gas Exchange**: Aerenchyma plays a crucial role in gas exchange. The air channels formed by aerenchyma facilitate the movement of oxygen and carbon dioxide between the submerged parts of the plant and the atmosphere. This is particularly important for plants that are partially or fully submerged in water.

4. **Distinguishing Functions**:
- **Buoyancy in Hydrophytes**: Aerenchyma helps hydrophytes float, which is vital for their exposure to sunlight for photosynthesis.
- **Absorption**: While absorption of water and nutrients primarily occurs in the epidermis of roots, aerenchyma does not play a significant role in this process.
- **Mechanical Strength**: Mechanical support in plants is mainly provided by sclerenchyma, not aerenchyma.
- **Flexibility**: The flexibility of plant tissues is typically attributed to collenchyma, not aerenchyma.

5. **Conclusion**: Based on the functions discussed, the correct answer to the question "Aerenchyma is helpful to plants by" is that it provides buoyancy to hydrophytes.

**Final Answer**: Aerenchyma is helpful to plants by providing buoyancy in hydrophytes.

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