Basis of stomatal opening is
A plant cell attains turgidity due to
Turgor pressure of a plant cell increases due to

Options

A. exosmosis
B. endosmosis
C. decreases in cell sap concentration
D. plasmolysis of fuard cells

Explanation

### Step-by-Step Text Solution

1. **Understanding Osmosis**:
- Osmosis is the movement of water from an area of higher concentration of solvent (water) to an area of lower concentration through a semi-permeable membrane. In plants, the cell membrane acts as this semi-permeable membrane.

2. **Water Movement into Plant Cells**:
- When a plant cell is placed in a hypotonic solution (where the concentration of water outside the cell is higher than inside), water moves into the cell due to osmosis. This influx of water occurs because the cell membrane allows water to pass while restricting solutes.

3. **Development of Turgor Pressure**:
- As water enters the cell, it exerts pressure against the cell wall. This pressure is known as turgor pressure. Turgor pressure is essential for maintaining the structure and rigidity of plant cells.

4. **Cell Turgidity**:
- As the turgor pressure increases, the volume of the cell enlarges, leading to a state called turgidity. A turgid cell is one that has taken in as much water as it can hold, and it cannot absorb more water at this point.

5. **Stomatal Opening**:
- The stomata are small openings on the surfaces of leaves that allow for gas exchange and transpiration. When the guard cells surrounding the stomata become turgid (due to the influx of water), they swell and cause the stomata to open. This opening allows excess water vapor to escape from the plant.

6. **Conclusion**:
- Therefore, the basis of stomatal opening, the turgidity of a plant cell, and the increase in turgor pressure are all interconnected processes that occur due to osmosis. Specifically, they are a result of endosmosis, where water moves into the cell, leading to turgidity and the opening of stomata.

### Final Answer:
The common cause for all three statements is **endosmosis**.

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