The correct option representing the structures forming phellogen , phellem and phelloderm is

Options

A. Phellogen : Cork cambium , Phellem, Secondary cortex and Phelloderm : Cork Secondary cortex and phelloderm : Cork
B. Phellogen : Cork cambium , Phellem: Cork and Phelloderm : Secondary cortex
C. Phellogen : Cork , Phellem: Secondary cortex and Phelloderm : Cork cambium
D. Phellogen : Secondary cortex , Phellem : Cork and Phellderm : cork cambium

Answer

To solve the question regarding the structures forming phellogen, phellem, and phelloderm, we need to understand the definitions and relationships of these terms in plant anatomy.

### Step-by-Step Solution:

1. **Identify the Terms**:
- **Phellogen**: This is the cork cambium, a layer of meristematic tissue that produces cork (phellem) on the outside and phelloderm on the inside.
- **Phellem**: This is the cork, which is produced by the phellogen and forms the outer protective layer of the plant.
- **Phelloderm**: This is the tissue produced by the phellogen on the inner side, which is usually living parenchyma cells.

2. **Analyze the Options**:
- **Option A**: Phellogen is formed by cork cambium, phellem by secondary cortex, and phelloderm by cork. This is incorrect because phellem is not formed by secondary cortex.
- **Option B**: Phellogen is cork cambium, phellem is cork, and phelloderm is formed by secondary cortex. This is correct as it accurately describes the relationships.
- **Option C**: Phellogen is cork, phellem is secondary cortex. This is incorrect because phellogen is not cork.
- **Option D**: Phellogen is formed by secondary cortex, and both phellem and phelloderm by cork cambium. This is incorrect as phellogen is not formed by secondary cortex.

3. **Conclusion**:
Based on the analysis, the correct option is **Option B**: Phellogen is formed by cork cambium, phellem is cork, and phelloderm is formed by secondary cortex.