In amoeboid type of tapetum

Options

A. The cells remain in situ
B. The cells secrete chemicals for degeneration of middle layers
C. The cells pass in between the middle layers
D. The cells form plasmodium that passes in between pollen grains mother cells.

Answer

### Step-by-Step Solution:

1. **Understanding the Structure of Microsporangium**:
- A microsporangium is a bilobed structure that contains layers such as the epidermis, endothecium, middle layer, and tapetum.
- The tapetum is the innermost layer surrounding the pollen mother cells (PMC).

2. **Identifying the Types of Tapetum**:
- There are different types of tapetum, including the amoeboid type.
- In the amoeboid type, the tapetal cells are characterized by their ability to fuse and form a plasmodium-like structure.

3. **Describing the Amoeboid Tapetum**:
- In the amoeboid type of tapetum, the cells are not static; they can fuse with each other.
- This fusion leads to the formation of a plasmodium, which is an irregular structure.

4. **Function of the Plasmodium**:
- The plasmodium formed by the fusion of tapetal cells can move and pass between the pollen mother cells.
- This movement is crucial for the nourishment and development of the pollen grains.

5. **Evaluating the Options**:
- **Option 1**: The cells remain in situ – Incorrect, as the cells do move.
- **Option 2**: The cells secrete chemicals for degeneration of middle layers – Incorrect, as degeneration does not occur in this context.
- **Option 3**: The cells pass in between middle layers – Incorrect, as they specifically pass to the pollen mother cells.
- **Option 4**: The cells form plasmodium that passes in between pollen grain mother cells – Correct, as this accurately describes the amoeboid tapetum.

6. **Conclusion**:
- The correct answer is **Option 4**: The cells form plasmodium that passes in between pollen grain mother cells.