Pneumatophores are

Options

A. Positively geotropic
B. Plagio-geotropic
C. Diageotropic
D. Negatively geotropic.

Answer

**Step-by-Step Solution:**

1. **Definition of Pneumatophores**: Pneumatophores are specialized root structures that are also known as breathing roots. They are adaptations found in certain plants, particularly mangrove trees.

2. **Function of Pneumatophores**: These roots help the plant to obtain oxygen from the air, especially in waterlogged conditions where the soil lacks sufficient oxygen.

3. **Geotropic Behavior**: Geotropism refers to the growth response of a plant to gravity. Roots typically exhibit positive geotropism (growing downwards), while shoots exhibit negative geotropism (growing upwards).

4. **Direction of Growth**: Pneumatophores grow upwards, which is opposite to the direction of gravity. This indicates that they are negatively geotropic.

5. **Phototropic Behavior**: In addition to being negatively geotropic, pneumatophores are also positively phototropic, meaning they grow towards light.

6. **Conclusion**: Based on the above points, we conclude that pneumatophores are negatively geotropic as they grow in the opposite direction to gravity.

**Final Answer**: Pneumatophores are negatively geotropic.

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