Water conduction in stem of tree takes place mainly by -

Options

A. Duramen
B. Sapwood
C. Primary xylem
D. All of the above

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about the main structure responsible for water conduction in the stem of a tree.

2. **Identifying the Options**: The options provided are:
- Duramen (Heartwood)
- Sapwood
- Primary Xylem
- All of the above

3. **Analyzing Duramen (Heartwood)**:
- Duramen, also known as heartwood, is the central part of the tree trunk.
- It consists of older xylem cells that have become lignified and contain substances like resin and oils.
- Although it provides mechanical support, it does not conduct water.

4. **Analyzing Sapwood**:
- Sapwood is the outer part of the xylem, located just beneath the bark.
- It is lighter in color and is responsible for the conduction of water and minerals from the roots to the leaves.
- This makes sapwood the primary tissue for water conduction in trees.

5. **Analyzing Primary Xylem**:
- Primary xylem is formed during the initial growth of the plant and is located closer to the center of the stem.
- In trees that undergo secondary growth, the primary xylem can become crushed and non-functional over time.

6. **Conclusion**:
- Since duramen does not conduct water and primary xylem is not functional in mature trees, the main structure responsible for water conduction in the stem of a tree is sapwood.
- Therefore, the correct answer is **Sapwood**.

### Final Answer:
Water conduction in the stem of a tree takes place mainly by **Sapwood**.

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