In trees absence of protoplast is essential for vital function such as

Options

A. food transport
B. water conduction
C. stomatal transpiration
D. both 1 and 2

Answer

To answer the question about the essential functions of protoplast absence in trees, we can break it down into the following steps:

### Step-by-Step Solution:

1. **Understanding Protoplast**: Protoplast refers to the living part of a plant cell, which includes the cell membrane and the contents within it, excluding the cell wall. In trees, protoplasts are crucial for various metabolic functions.

2. **Role of Xylem**: In trees, water and mineral transport primarily occurs through specialized tissues called xylem vessels and tracheids. These structures are responsible for conducting water from the roots to the leaves.

3. **Lignification and Cell Death**: Over time, xylem vessels undergo a process called lignification, where they become reinforced with lignin, a complex organic polymer. This process leads to the death of the protoplasts within these cells, resulting in hollow tubes that facilitate efficient water transport.

4. **Importance of Dead Xylem**: The absence of protoplasts in xylem vessels is essential because it allows these vessels to function as conduits for water and minerals. The dead cells create a continuous column for water movement, which is aided by adhesive and cohesive forces.

5. **Vital Functions Supported by Xylem**: The vital functions supported by the absence of protoplasts in xylem include:
- **Water Conduction**: The primary function of xylem is to transport water from the roots to the rest of the plant.
- **Mineral Transport**: Along with water, essential minerals are also transported through the xylem.
- **Support**: The lignified walls of xylem provide structural support to the plant.

6. **Conclusion**: Therefore, the absence of protoplasts in xylem vessels is crucial for the vital functions of water and mineral conduction in trees.