In the following, how the sapwood is converted into heartwood?

Options

A. A. By degeneration of protoplast of living cells
B. B. Tyloses formation
C. C. By deposition of resins, oil , gums
D. D. All of the above

Answer

**Step-by-Step Solution:**

1. **Understanding Sapwood and Heartwood**:
- Sapwood is the outer, living part of the tree that is responsible for the transport of water and nutrients. Heartwood, on the other hand, is the inner, non-living part that provides structural support and is typically darker in color.

2. **Degeneration of Protoplast**:
- The conversion of sapwood into heartwood begins with the degeneration of the protoplast (the living part of the cell) in the xylem cells. As these protoplasts degenerate, the cells lose their living functions, leading to the formation of heartwood, also known as duramen.

3. **Formation of Tylosis**:
- Tylosis is the outgrowth of parenchyma cells that occurs in the xylem. This process is often triggered by stress conditions such as infection or drought. Tylosis helps to block the vascular tissues, preventing further damage and contributing to the transition from sapwood to heartwood.

4. **Deposition of Resins, Oils, and Gums**:
- As the wood matures, various substances like resins, tannins, and oils are deposited in the heartwood. This deposition not only contributes to the darker color of heartwood but also enhances its durability and resistance to decay.

5. **Conclusion**:
- All the processes mentioned (degeneration of protoplasts, formation of tylosis, and deposition of resins, oils, and gums) are involved in the conversion of sapwood into heartwood. Therefore, the correct answer is that all of the above processes contribute to this conversion.

**Final Answer**: All of the above processes contribute to the conversion of sapwood into heartwood.

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