Which layer of the anther wall is the not derived from archesporium?

Options

A. epidermis
B. endothecium
C. middle layer
D. tapetum

Answer

To solve the question "Which layer of the anther wall is not derived from archesporium?" we need to analyze the structure and development of the anther.

### Step-by-Step Solution:

1. **Understanding the Structure of the Anther**:
- The anther is a part of the stamen in flowering plants and is responsible for producing pollen. It typically consists of four pollen sacs.

2. **Identifying the Layers of the Anther**:
- The anther wall consists of several layers:
- Epidermis
- Endothesium
- Middle layer
- Tapetum

3. **Role of Archesporium**:
- The archesporium is a layer of cells in the young anther that gives rise to several structures. It differentiates into:
- Microspore mother cells (which develop into pollen grains)
- Endothesium
- Middle layer
- Tapetum

4. **Determining the Origin of Each Layer**:
- **Epidermis**: This layer is derived from the outermost layer of the young anther and is not formed from the archesporium.
- **Endothesium, Middle Layer, and Tapetum**: These layers are all derived from the archesporium.

5. **Conclusion**:
- Since the epidermis is the only layer that is not derived from the archesporium, the correct answer to the question is **Epidermis**.

### Final Answer:
The layer of the anther wall that is not derived from archesporium is **Epidermis**.

---