What is the main function of anti-transpirants ?

Options

A. Reduce the rate of transpiration without affecting carbon assimilation
B. Reduce the rate of transpiration affecting carbon assimilation
C. Reduce the rate of transpiration affecting growth of plants
D. Reduce the rate of transpiration affecting protein synthesis of plant

Answer

To answer the question regarding the main function of anti-transpirants, we can break down the information as follows:

### Step-by-Step Solution:

1. **Definition of Anti-transpirants**:
Anti-transpirants are compounds that are applied to the surface of leaves. Their primary purpose is to reduce the rate of transpiration in plants.

**Hint**: Remember that anti-transpirants are specifically designed to affect transpiration rates.

2. **Mechanism of Action**:
These compounds work by reducing the stomatal opening on the leaves. Stomata are small openings that allow for gas exchange (including water vapor) between the plant and the environment.

**Hint**: Focus on how anti-transpirants influence stomatal behavior.

3. **Effect on Water Vapor Diffusion**:
By reducing the stomatal opening, anti-transpirants increase the resistance of the leaf to water vapor diffusion. This means that less water is lost through transpiration.

**Hint**: Consider what happens to water loss when stomata are less open.

4. **Impact on Carbon Assimilation**:
Importantly, while anti-transpirants reduce transpiration, they do not significantly affect the uptake of carbon dioxide (CO2) for photosynthesis. This means that the process of carbon assimilation remains largely unaffected.

**Hint**: Think about the relationship between transpiration and carbon dioxide uptake.

5. **Conclusion**:
Based on the above points, the main function of anti-transpirants is to reduce the rate of transpiration without affecting carbon assimilation. Therefore, the correct answer to the question is:

**Answer**: Reduce the rate of transpiration without affecting carbon assimilation.

### Summary of the Main Function:
The primary function of anti-transpirants is to minimize water loss through transpiration while allowing the plant to continue its essential process of carbon assimilation, ensuring that it does not suffer from drought stress.