Endothecium takes part in

Options

A. Dehiscence of anther
B. Nourishment of microspore mother cells
C. Nourishment of pollen grains
D. Synthesis of pollen grain wall.

Answer

To answer the question "Endothecium takes part in," we need to analyze the functions of the endothecium in the context of the structure of the anther.

### Step-by-Step Solution:

1. **Understanding the Structure of the Anther**:
- The anther is part of the stamen in flowering plants and consists of several layers. The key layers include the epidermis, endothecium, middle layer, and tapetum.

2. **Identifying the Role of Each Layer**:
- **Epidermis**: The outermost layer that primarily provides protection.
- **Endothecium**: This is a fibrous layer that plays a crucial role in the dehiscence of the anther.
- **Middle Layer**: This layer has a supportive role but is not primarily involved in nourishment.
- **Tapetum**: This innermost layer is responsible for nourishing the microspore mother cells and pollen grains, as well as synthesizing the pollen grain wall.

3. **Focusing on the Endothecium**:
- The endothecium is specifically involved in the process of dehiscence, which is the breaking open of the anther to release mature pollen grains. This occurs when the microsporangium is fully matured.

4. **Evaluating the Options**:
- **Option 1**: Dehiscence of anther - This is the correct function of the endothecium.
- **Option 2**: Nourishment of microspore mother cells - This is a function of the tapetum.
- **Option 3**: Nourishment of pollen grains - This is also a function of the tapetum.
- **Option 4**: Synthesis of pollen grain wall - This is another function of the tapetum.

5. **Conclusion**:
- Based on the analysis, the endothecium's primary role is in the dehiscence of the anther. Therefore, the correct answer is **Option 1**: dehiscence of anther.

### Final Answer:
Endothecium takes part in the dehiscence of anther (Option 1).