During the opening of stomata, the organic malate ions are produced in the guard cells for maintaining the

Options

A. (a) Negative voltage to take in potassium ions
B. (b) Photosynthetic products in active osmotic form
C. (c) Calcium ions in lesser concentration
D. (d) Respiratory pathway in aerobic mode

Answer

**Step-by-Step Solution:**

1. **Understanding the Role of Guard Cells:**
- Guard cells are specialized cells located around the stomata (small openings on the leaf surface) that regulate gas exchange by controlling the opening and closing of these stomata.

**Hint:** Remember that guard cells are like gates that control the entry and exit of gases in plants.

2. **Mechanism of Stomatal Opening:**
- The opening of stomata is primarily influenced by the uptake of potassium ions (K+) into the guard cells. This process is explained by the potassium pump hypothesis.

**Hint:** Think about how the movement of ions can affect the pressure within the cells.

3. **Production of Malate Ions:**
- During the process of photosynthesis, malic acid is produced in the chloroplasts of guard cells, which is then converted into malate ions. This conversion is crucial for maintaining osmotic balance.

**Hint:** Consider how photosynthesis contributes to the production of substances that affect cell turgor.

4. **Increase in Turgor Pressure:**
- The accumulation of potassium ions and malate ions in guard cells leads to an increase in turgor pressure. This is because the influx of these ions lowers the water potential in the guard cells, causing water to enter the cells via osmosis.

**Hint:** Recall that turgor pressure is essential for maintaining the structure and function of plant cells.

5. **Stomatal Opening:**
- As the guard cells become turgid (swollen with water), they bend and cause the stomata to open, allowing for gas exchange (CO2 in, O2 out) necessary for photosynthesis.

**Hint:** Visualize how the shape of guard cells changes as they fill with water.

6. **Conclusion:**
- The production of organic malate ions in guard cells is essential for maintaining the osmotic balance and facilitating the opening of stomata, which is crucial for the plant's gas exchange process.

**Hint:** Summarize how the interplay of ions and water movement leads to the opening of stomata.

**Final Answer:**
The organic malate ions produced in the guard cells are essential for maintaining the osmotic pressure, which facilitates the opening of stomata.