heart wood differs from sapwood in

Options

A. presence of rays and fibres
B. absence of vessels and parenchyma
C. having dead and non -conducting elements
D. being susceptible to pests and pathogens

Answer

### Step-by-Step Solution:

1. **Understanding Heartwood and Sapwood**:
- Heartwood and sapwood are two distinct types of wood found in woody plants.
- Heartwood is the inner part of the tree, while sapwood is the outer part.

2. **Composition of Heartwood**:
- Heartwood is primarily composed of dead xylem vessels.
- These vessels are filled with tyloses, which are balloon-shaped outgrowths.
- Heartwood is rich in deposits of resins and tannins, which contribute to its darker appearance.

3. **Functionality**:
- The vessels in heartwood are non-functional, meaning they do not conduct water or nutrients.
- In contrast, sapwood contains newly formed and functional vessels that are actively involved in the conduction of water and nutrients.

4. **Appearance**:
- Heartwood typically appears darker due to the presence of these deposits.
- Sapwood appears lighter because it consists of living, functional cells.

5. **Resistance to Pests**:
- Heartwood provides resistance against pests and pathogens due to the presence of chemical compounds like resins and tannins.
- This makes heartwood more durable compared to sapwood.

6. **Conclusion**:
- The main difference between heartwood and sapwood is that heartwood consists of dead and non-conducting elements, while sapwood contains living and functional elements.

### Final Answer:
Heartwood differs from sapwood in that it contains dead and non-conducting elements.

---