Shape, size, cell elongation, ability of roots piercing through hard floors is all due to

Options

A. Plasmolysis
B. Guttation
C. Turgor pressure
D. Water potential

Answer

To solve the question regarding the factors influencing the shape, size, cell elongation, and the ability of roots to pierce through hard surfaces, we can break down the concepts as follows:

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about the physiological factors that contribute to the shape, size, cell elongation, and the ability of roots to penetrate hard surfaces.

2. **Identifying Key Terms**: The options given are plasmolysis, guttation, trigger pressure, and water potential. We need to analyze these terms in relation to plant physiology.

3. **Analyzing Each Option**:
- **Plasmolysis**: This refers to the process where cells lose water in a hypertonic solution, causing the cell membrane to pull away from the cell wall. This does not contribute positively to cell elongation or root penetration.
- **Guttation**: This is the process of exuding water droplets from the leaves of plants, usually occurring at night. It is related to water loss and does not directly affect root growth or cell shape.
- **Trigger Pressure**: This is the pressure exerted by the fluid (water) within the cell that pushes against the cell wall. It is crucial for maintaining cell turgor, which is essential for cell elongation, shape, and the ability of roots to grow through hard substrates.
- **Water Potential**: This refers to the potential energy of water in a system compared to pure water. While it influences water movement, it is not a direct cause of the physical characteristics mentioned in the question.

4. **Conclusion**: The primary factor responsible for the shape, size, cell elongation, and the ability of roots to penetrate hard surfaces is **trigger pressure**. This pressure is generated by the presence of water within the cells, which helps maintain turgor pressure, allowing cells to elongate and roots to grow effectively.

### Final Answer:
The correct answer is **trigger pressure**.

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