The periderm includes

Options

A. Secondary pholem
B. Cork
C. Cambium
D. All of these

Answer

**Step-by-Step Solution:**

1. **Understanding Periderm**: The periderm is a protective layer that replaces the epidermis in plants during secondary growth. It consists of multiple layers that serve to protect the plant from environmental damage and water loss.

2. **Components of Periderm**: The periderm is made up of three main components:
- **Cork (Phellem)**: This is the outermost layer of the periderm. It is composed of dead cells that provide a protective barrier.
- **Cork Cambium (Phellogen)**: This is a layer of meristematic tissue that produces cork cells towards the outside and secondary cortex (phelloderm) towards the inside.
- **Secondary Cortex (Phelloderm)**: This is the inner layer produced by the cork cambium, which consists of living cells.

3. **Identifying the Correct Answer**: The question asks what the periderm includes. The options provided are secondary phloem, cork, and cambium.
- The cork is a primary component of the periderm.
- The cork cambium is also part of the periderm but is not the same as the periderm itself.
- Secondary phloem is not part of the periderm; it is formed from the vascular cambium.

4. **Conclusion**: Based on the definitions and components, the periderm includes the cork and the cork cambium but primarily refers to the cork. Therefore, the correct answer is **cork**.