Mushroom buttons and grass seeds often break the asphalt and concrete pavements due to

Options

A. diffusion pressure
B. root pressure
C. imbibition pressure
D. plasmolysis

Answer

**Step-by-Step Solution:**

1. **Understanding the Structure of Seeds**:
- Grass seeds contain an embryo that is protected by a hard outer layer known as the seed coat. The seed coat is a dead structure but is permeable to water.

2. **Process of Imbibition**:
- When grass seeds are soaked in water, the seed coat absorbs the water. This process is called imbibition, which is the absorption of water due to surface attraction.

3. **Swelling of the Seed Coat**:
- As the seed coat absorbs water, it swells. This swelling creates internal pressure within the seed.

4. **Imbibition Pressure**:
- The pressure that develops due to the swelling of the seed coat is referred to as imbibition pressure. This pressure is strong enough to exert force on surrounding structures.

5. **Impact on Pavements**:
- When grass seeds or mushroom buttons germinate, the imbibition pressure can be significant enough to break through hard surfaces like asphalt and concrete pavements.

6. **Conclusion**:
- Therefore, the breaking of asphalt and concrete pavements by mushroom buttons and grass seeds is primarily due to the imbibition pressure generated during the absorption of water by the seed coat.

**Final Answer**: The breaking of asphalt and concrete pavements by mushroom buttons and grass seeds is due to imbibition pressure.

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