Transport of substance over small distance occurs by

Options

A. Diffusion
B. Cytoplasmic streaming
C. Osmosis
D. Both (1) and (2) are correct

Answer

**Step-by-Step Text Solution:**

1. **Understanding the Question**: The question asks about the transport of substances over small distances in plants. We need to identify the processes that facilitate this transport.

2. **Analyzing Option 1 - Diffusion**:
- **Definition**: Diffusion is the movement of substances from an area of higher concentration to an area of lower concentration.
- **Example**: For instance, if there is a higher concentration of water outside a plant cell compared to the inside, water will move into the cell through diffusion.
- **Conclusion**: Diffusion is indeed a process that can transport substances over small distances.

3. **Analyzing Option 2 - Cytoplasmic Streaming**:
- **Definition**: Cytoplasmic streaming (or protoplasmic streaming) refers to the movement of the fluid substance within a plant cell, facilitating the exchange of nutrients and organelles.
- **Function**: It aids in both short and long-distance transport of substances within the cell.
- **Conclusion**: Cytoplasmic streaming is also a valid process for transporting substances over small distances.

4. **Analyzing Option 3 - Osmosis**:
- **Definition**: Osmosis is the movement of water across a semi-permeable membrane from an area of lower solute concentration to an area of higher solute concentration.
- **Context**: While osmosis is crucial for water transport in plants, it primarily involves the movement of water rather than other substances, and it is not specifically for short distances.
- **Conclusion**: Osmosis does not primarily pertain to the transport of various substances over small distances.

5. **Final Evaluation of Options**:
- **Option 1** (Diffusion) is correct for small distance transport.
- **Option 2** (Cytoplasmic Streaming) is also correct for small distance transport.
- **Option 3** (Osmosis) is not primarily about small distance transport of substances.
- **Option 4** states that both options 1 and 2 are correct, which is accurate.

6. **Final Answer**: Therefore, the correct answer to the question "Transport of substances over small distances occurs by" is **Option 4: Both 1 and 2 are correct**.

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