Identify the incorrect statement.

Options

A. Movement of substances over short distances occurs by diffusion
B. Cytoplasmic streaming supports short distance transport
C. Short distance transport is also supported by active transport
D. Movement of substances over small distances occurs through vascular system only

Answer

To identify the incorrect statement regarding transport in plants, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Examine Statement 1**: "Movement of substances over short distances occurs by diffusion."
- **Analysis**: This statement is correct. Diffusion is a passive transport mechanism that allows substances to move from areas of higher concentration to areas of lower concentration. In plants, diffusion is commonly involved in the movement of gases and water vapor.

2. **Examine Statement 2**: "Cytoplasmic streaming supports short distance transport."
- **Analysis**: This statement is also correct. Cytoplasmic streaming is the movement of the cytoplasm within a cell, facilitating the transport of materials over short distances. It is particularly evident in certain plant cells, such as those in the leaves of Hydrilla.

3. **Examine Statement 3**: "Short distance transport is supported by active transport."
- **Analysis**: This statement is correct as well. Active transport uses energy (ATP) to move substances against their concentration gradient, and it can occur over short distances within plant cells.

4. **Examine Statement 4**: "Movement of substances over small distances occurs through the vascular system."
- **Analysis**: This statement is incorrect. The vascular system (xylem and phloem) is primarily responsible for the long-distance transport of water, nutrients, and sugars throughout the plant. Short-distance transport typically occurs via diffusion, cytoplasmic streaming, and active transport, not through the vascular system.

### Conclusion:
The incorrect statement is **Statement 4**: "Movement of substances over small distances occurs through the vascular system."

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