Sulphur dioxide affects

Options

A. Cell wall
B. Plasmodesmata
C. All membrane system
D. Nucleus.

Answer

### Step-by-Step Solution:

1. **Understanding Sulphur Dioxide**: Sulphur dioxide (SO₂) is a common air pollutant that is primarily emitted from vehicles and industrial processes. It is known for its harmful effects on the environment and human health.

2. **Effects of Sulphur Dioxide**:
- It acts as an oxidizing agent, which means it can disrupt various biological systems.
- One of the significant environmental impacts of sulphur dioxide is its contribution to acid rain. When sulphur dioxide combines with water vapor in the atmosphere, it forms sulphuric acid, which can fall as acid rain.

3. **Impact on Biological Structures**:
- The question asks about the effects of sulphur dioxide on specific cellular structures: cell wall, plasmodesmata, membrane system, and nucleus.
- **Cell Wall**: The cell wall is the outer protective layer of plant cells. Sulphur dioxide does not significantly affect the cell wall, making this option incorrect.
- **Plasmodesmata**: These are channels that allow communication between plant cells. Sulphur dioxide does not have a direct effect on plasmodesmata, so this option is also incorrect.
- **Membrane System**: Sulphur dioxide disrupts the transport systems associated with the membrane. Its oxidizing nature can damage the membranes of cells, affecting their function. Therefore, this option is correct.
- **Nucleus**: Sulphur dioxide does not typically interfere with the nucleus or cause mutations, making this option incorrect.

4. **Conclusion**: Based on the analysis, the correct answer is that sulphur dioxide affects the **membrane system** of organisms.

### Final Answer:
Sulphur dioxide affects the **membrane system**.