Bark of a tree consists of:

Options

A. all dead tissues
B. all tissues outside the vascular cambium
C. all tissues outside the cork cambium
D. the cork and secondary cortex

Explanation

### Step-by-Step Solution:

1. **Understanding the Structure of Bark**:
- The bark of a tree is the outermost layer that protects the tree. It is important to understand what constitutes the bark.

2. **Identifying the Components of Bark**:
- The bark is made up of various tissues that are located outside the vascular cambium. The vascular cambium is a layer of tissue that produces new vascular tissue (xylem and phloem).

3. **Defining the Layers of Bark**:
- The bark includes several layers:
- **Periderm**: This is the outer layer of bark, which consists of:
- **Phellogen**: The cork cambium that produces cork cells.
- **Phellum**: The cork cells that are produced by the phellogen, which are dead and provide protection.
- **Phelloderm**: The layer of living cells produced by the phellogen.
- **Primary Cortex**: This is the layer beneath the periderm.
- **Pericycle**: A layer of cells that can give rise to new roots.
- **Primary and Secondary Phloem**: These are involved in the transport of nutrients.

4. **Analyzing the Options**:
- The options given were:
1. All dead tissues
2. All tissues outside the vascular cambium
3. All tissues outside the cork cambium
4. The cork and the secondary cortex
- The correct option is **"all tissues outside the vascular cambium"** because bark includes both living and dead tissues outside this layer.

5. **Conclusion**:
- Therefore, the bark of a tree consists of all the tissues that are located outside the vascular cambium.