In trees, death of protoplasts is essential for a vital function such as

Options

A. Food transport
B. Water transport
C. Both 1 and 2
D. Stomatal movements

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about the significance of the death of protoplasts in trees and its relation to vital functions.

2. **Identifying the Functions**: The options provided include:
- Food transport
- Water transport
- Stomatal movement

3. **Analyzing Water Transport**:
- Water transport in plants primarily occurs through the xylem, which consists of dead cells (tracheids and vessels) at maturity.
- The process of water transport is driven by transpirational pull, which is a physical process and does not require living cells.

4. **Analyzing Food Transport**:
- Food transport occurs through the phloem, which consists of living cells.
- This process is physiological and requires living protoplasts to function properly, as it involves the movement of nutrients and signaling.

5. **Analyzing Stomatal Movement**:
- Stomatal movement is also a physiological process that requires living cells to sense and respond to environmental conditions.
- This process involves guard cells that regulate the opening and closing of stomata.

6. **Conclusion**: Since the death of protoplasts is essential for the physical process of water transport but not for food transport or stomatal movement, the correct answer is that the death of protoplasts is essential for water transport.

### Final Answer:
The death of protoplasts in trees is essential for the vital function of **water transport**.

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