Incorrect statement with regard to ‘diffusion’ is

Options

A. It is a slow process and is dependent on a ‘living system’
B. Diffusion in solids rather than of solids is more likely
C. Gaseous movement within the plant body occurs by means of diffusion only
D. Rate of diffusion is affected by temperature and pressure.

Answer

To determine the incorrect statement regarding diffusion, let's analyze the options provided step by step.

### Step-by-Step Solution:

1. **Understanding Diffusion**:
- Diffusion is the movement of molecules from an area of higher concentration to an area of lower concentration. It is a passive process that does not require energy.

2. **Evaluating the First Option**:
- The first option states that "diffusion is a slow process and it is dependent on living systems."
- While it is true that diffusion is a slow process, it is **not dependent on living systems**. Diffusion can occur in both living and non-living systems. Therefore, this statement is incorrect.

3. **Evaluating the Second Option**:
- The second option mentions that "diffusion in solids is more likely than in liquids."
- This statement is misleading. In general, diffusion occurs more readily in liquids and gases than in solids due to the greater mobility of molecules. Hence, this statement is also incorrect.

4. **Evaluating the Third Option**:
- The third option states that "gaseous movement within the plant body occurs by means of diffusion only."
- This statement is correct. In plants, gases such as oxygen and carbon dioxide move primarily through diffusion.

5. **Evaluating the Fourth Option**:
- The fourth option claims that "the rate of diffusion is affected by temperature and pressure."
- This statement is true. An increase in temperature typically increases the rate of diffusion, as does a decrease in pressure.

### Conclusion:
Based on the analysis, the incorrect statement regarding diffusion is the first option: "diffusion is a slow process and it is dependent on living systems."