Polygonum type of embryo sac is

Options

A. 8-nucleate, 7-celled
B. 8-nucleate , 8-celled
C. 7-nucleate, 7-celled
D. 4-nucleate, 3-celled

Answer

### Step-by-Step Solution:

1. **Understanding the Embryo Sac**:
- The embryo sac is the female gametophyte of angiosperms (flowering plants). It plays a crucial role in reproduction as it contains the egg cell and other cells involved in fertilization.

2. **Identifying the Polygonum Type**:
- The Polygonum type of embryo sac is characterized by a specific arrangement of nuclei and cells.

3. **Counting Nuclei and Cells**:
- In the Polygonum type, there are a total of **8 nuclei** and **7 cells**. This is a key feature that distinguishes it from other types of embryo sacs.

4. **Formation of Nuclei and Cells**:
- The formation of the 8 nuclei and 7 cells occurs through **3 mitotic divisions** of the initial cell. This process results in the development of the various cells within the embryo sac.

5. **Arrangement of Cells**:
- The arrangement of the cells in the Polygonum type embryo sac includes:
- **3 antipodal cells** at the upper end.
- **2 synergids** and **1 egg cell** in the middle.
- **1 central cell** that contains **2 polar nuclei**.

6. **Conclusion**:
- Therefore, the Polygonum type of embryo sac is **8-nucleate and 7-celled**.