sap-wood is

Options

A. Peripheral region of secondary xylem
B. Lighter in colour
C. Involved in conduction of water and minerals
D. Living and physiologically non-functional region

Answer

### Step-by-Step Text Solution:

1. **Definition of Sapwood**:
- Sapwood, also known as **alburnum**, is the outer layer of secondary wood in a plant.

**Hint**: Remember that sapwood is also referred to by another name, which is important for understanding its identity.

2. **Characteristics of Sapwood**:
- It is the **living layer** of the wood, meaning it is actively involved in physiological processes.

**Hint**: Focus on the fact that sapwood is not just structural but also functional.

3. **Function of Sapwood**:
- The primary function of sapwood is to **transport water and minerals** throughout the plant.

**Hint**: Think about the role of sapwood in the plant's overall health and nutrient distribution.

4. **Color and Texture**:
- Sapwood is generally **lighter in color** compared to heartwood because it lacks darker staining chemical substances.

**Hint**: Consider how the absence of certain chemicals affects the appearance of sapwood.

5. **Comparison with Heartwood**:
- Heartwood is the older, inner layer of secondary wood that is **darker and harder** due to the presence of these chemical substances.

**Hint**: Understanding the differences between sapwood and heartwood can help clarify their respective functions.

6. **Analysis of Options**:
- The options given include:
1. Peripheral region of the secondary xylem (True)
2. Lighter in color (True)
3. Involved in conduction of water and minerals (True)
4. Living and physiological non-functional reasons (False)

- The last option is incorrect because sapwood is indeed living and functional, contrary to what the option suggests.

**Hint**: When evaluating options, look for contradictions in the definitions and functions provided.

### Final Answer:
The incorrect option regarding sapwood is: **"Living and physiological non-functional reasons."**