Bark includes

Options

A. Periderm + Secondary pholem
B. Periderm + primary xylem
C. Secondary phloem + xylem
D. Secondary xylem + Cork cambium

Answer

### Step-by-Step Solution:

1. **Understanding Bark**: Bark is defined as the outermost layer of stems and roots in woody plants. It encompasses all tissues outside the vascular cambium.

2. **Components of Bark**: Bark consists of two main parts:
- **Inner Bark**: This is the living tissue that includes the innermost area of the periderm.
- **Outer Bark**: This is primarily made up of dead tissues and protects the inner layers.

3. **Identifying the Correct Components**:
- The bark includes periderm (the protective outer layer) and secondary phloem (the tissue responsible for transporting nutrients).
- It does not include primary xylem or secondary xylem as these are components of wood.

4. **Evaluating Options**:
- **Option 1**: Periderm + Secondary Phloem - This is a correct combination as both are part of the bark.
- **Option 2**: Periderm + Primary Xylem - This is incorrect because primary xylem is part of the wood, not bark.
- **Option 3**: Secondary Phloem + Xylem - This is incorrect as xylem is not part of the bark.
- **Option 4**: Secondary Xylem + Cork Cambium - This is also incorrect since secondary xylem is part of the wood.

5. **Conclusion**: The correct answer is that bark includes **periderm plus secondary phloem**.