In a dicot stem, youngest layer of secondary xylem is situated

Options

A. In between pith and primary xylem
B. Just outside the vascular cambium
C. Just on inner side of the vascular cambium
D. Just inside the phellogen

Answer

To determine the location of the youngest layer of secondary xylem in a dicot stem, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Structure of a Dicot Stem**:
- A dicot stem consists of several layers, starting from the outermost layer (epidermis) to the innermost layer (pith).

2. **Identify the Layers**:
- The layers in a dicot stem from outside to inside are:
- Epidermis
- Cortex
- Primary Phloem
- Primary Xylem
- Vascular Cambium
- Secondary Phloem
- Secondary Xylem
- Pith

3. **Locate the Vascular Cambium**:
- The vascular cambium is a layer of meristematic tissue that is responsible for the production of secondary xylem and secondary phloem.

4. **Identify the Position of Secondary Xylem**:
- The secondary xylem is produced by the vascular cambium. Therefore, the youngest layer of secondary xylem is located just inside the vascular cambium.

5. **Clarify Misconceptions**:
- The youngest layer of secondary xylem is not located between the pith and primary xylem. Instead, it is directly adjacent to the vascular cambium.

6. **Conclusion**:
- The youngest layer of secondary xylem in a dicot stem is situated just inside the vascular cambium.

### Final Answer:
The youngest layer of secondary xylem in a dicot stem is situated just inside the vascular cambium.

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