Besides phellem, phellogen, root periderm comprises of

Options

A. Secondary cortex
B. Phelloderm
C. Bark
D. More than one option is correct

Answer

To answer the question "Besides phellem, phellogen, root periderm comprises of," we need to analyze the components of root periderm and identify the correct answer.

### Step-by-Step Solution:

1. **Understanding Periderm**:
- The periderm is a protective tissue that replaces the epidermis in roots and stems as they mature. It is formed from secondary growth and consists of three main layers.

2. **Identifying the Layers**:
- The three layers of periderm are:
- **Phellem**: Also known as cork, it is the outermost layer that provides protection.
- **Phellogen**: Also known as cork cambium, it is the meristematic layer that produces phellem and phelloderm.
- **Phelloderm**: This is the innermost layer of the periderm, which is formed by the phellogen.

3. **Analyzing the Question**:
- The question specifies "besides phellem and phellogen." This means we need to identify what else is included in the periderm apart from these two layers.

4. **Conclusion**:
- The remaining component of the periderm, which is not mentioned in the question, is **phelloderm**. Therefore, the answer to the question is that root periderm comprises of **phelloderm** in addition to phellem and phellogen.

### Final Answer:
Root periderm comprises of **phelloderm** besides phellem and phellogen.

---