The collective term used for phelloderm (secondary cortex), cork cambium (phellogen) and cork (phellem) is

Options

A. pericycle
B. periderm
C. protoderm
D. ring,scaly

Answer

To answer the question regarding the collective term used for phelloderm (secondary cortex), cork cambium (phellogen), and cork (phellem), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Components**:
- The components mentioned in the question are:
- Phelloderm (secondary cortex)
- Cork cambium (phellogen)
- Cork (phellem)

2. **Understand the Function of Each Component**:
- **Phelloderm**: This is the inner layer of the periderm, which is a secondary protective tissue.
- **Cork Cambium**: Also known as phellogen, this is a lateral meristem that produces cork cells and phelloderm.
- **Cork**: Known as phellem, this is the outer layer that provides protection to the plant.

3. **Collective Term for the Components**:
- The collective term that encompasses phelloderm, cork cambium, and cork is known as **periderm**.

4. **Explanation of Periderm**:
- Periderm acts as a secondary protective covering for woody stems and some non-woody plants. It replaces the epidermis and serves as a protective layer.

5. **Conclusion**:
- Therefore, the answer to the question is **periderm**.

### Final Answer:
The collective term used for phelloderm, cork cambium, and cork is **periderm**.

---