Termites usually does not attack/most durable part of woods is

Options

A. alburnum
B. duramen
C. periderm
D. bark

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks which durable part of wood termites usually do not attack. We need to identify the correct part of wood from the given options: alburnum, duramen, periderm, or bark.

2. **Analyzing the Options**:
- **Periderm**: This is a protective tissue that consists of three layers (phalloderm, phallogen, and phallum) and is located outside the epidermis. Since it is not part of the wood, we can eliminate this option.
- **Bark**: Bark serves as a protective layer and is involved in the transport of food within the tree. It is also not a part of the wood structure, so we can eliminate this option as well.
- **Alburnum**: Also known as sapwood, this is the living and functional part of the secondary xylem. It has a larger lumen and is more susceptible to attack by termites.
- **Duramen**: Known as heartwood, this is the central part of the tree that is non-functional and dead. It has a smaller lumen, is dark in color, and is much harder due to the presence of tyloses, making it resistant to microorganisms, including termites.

3. **Conclusion**: Based on the analysis, the most durable part of wood that termites usually do not attack is the **duramen** (heartwood).

**Final Answer**: Duramen

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