Periderm includes

Options

A. Phellem, phellogen and phelloderm
B. Phellem and phellogen only
C. Phellogen and phelloderm only
D. Vascular and cork cambia only

Answer

To answer the question "Periderm includes," we need to understand the components that make up the periderm in plants. Here’s a step-by-step breakdown:

### Step-by-Step Solution:

1. **Understanding Periderm**:
- Periderm is a protective layer that replaces the epidermis in plants during secondary growth. It forms when the epidermal cells are damaged or when the plant grows in diameter.

2. **Components of Periderm**:
- The periderm consists of three main components:
- **Phellem**: Also known as cork, this is the outermost layer of the periderm. It provides protection and prevents water loss.
- **Phelogen**: This is the cambium-like layer that produces phellem (cork) on the outside and pheloderm on the inside. It is responsible for the secondary growth of the periderm.
- **Pheloderm**: This is the inner layer of the periderm, which is made up of living cells that can store nutrients and provide some metabolic functions.

3. **Conclusion**:
- Therefore, the periderm includes all three components: phellem, phelogen, and pheloderm.

4. **Final Answer**:
- The correct option is: **Phellem, Phelogen, and Pheloderm**.