which is not part of periderm

Options

A. Phellogen
B. Cork
C. Secondary cortex
D. Wood

Answer

To determine which option is not part of the periderm, we need to understand what the periderm consists of. The periderm is a protective tissue that replaces the epidermis in plants during secondary growth. It is primarily made up of three components:

1. **Phellogen (Cork Cambium)**: This is a type of lateral meristem that produces cork cells towards the outside and secondary cortex (or phelloderm) towards the inside.

2. **Cork (Phellem)**: These are the protective cells produced by the phellogen towards the outside. Cork cells are dead at maturity and serve as a barrier against physical damage and pathogens.

3. **Secondary Cortex (Phelloderm)**: This is the tissue produced by the phellogen towards the inside. It consists of living parenchyma cells that can store nutrients.

Now, let's analyze the options provided:

- **Fallogen (Phellogen)**: This is part of the periderm.
- **Cork (Phellem)**: This is also part of the periderm.
- **Secondary Cortex (Phelloderm)**: This is included in the periderm as well.
- **Wood**: This is not part of the periderm. Wood is primarily composed of xylem, which is located inside the stelar region and is not involved in the formation of the periderm.

From this analysis, we conclude that the correct answer to the question "which is not part of periderm" is **Wood**.

### Step-by-Step Solution:
1. Understand the components of the periderm: Phellogen, Cork, and Secondary Cortex.
2. Analyze the options given in the question.
3. Identify that Phellogen, Cork, and Secondary Cortex are all part of the periderm.
4. Recognize that Wood is not part of the periderm, as it is located in the stelar region and consists mainly of xylem.
5. Conclude that the answer is Wood.