Typical embryosac of angiosperms is

Options

A. Tetranucleated
B. Eight-nucleated and seven-celled
C. Tetranucleated and seven-celled
D. Tetranucleated and tetra-celled

Answer

To answer the question about the typical embryo sac of angiosperms, we will follow these steps:

### Step-by-Step Solution:

1. **Understanding the Embryo Sac**:
- The embryo sac in angiosperms is also known as the mature female gametophyte. It is crucial to know its structure and components.

2. **Identifying the Structure**:
- The typical embryo sac consists of a total of seven cells and eight nuclei. This is a key characteristic of the angiosperm embryo sac.

3. **Counting the Cells**:
- The embryo sac has three antipodal cells at the chalazal end.
- At the micropilar end, there are three synergid cells.
- Additionally, there is one central cell which contains two polar nuclei.
- Therefore, the total number of cells is:
- 3 (antipodal) + 3 (synergids) + 1 (central cell) = 7 cells.

4. **Counting the Nuclei**:
- Each of the three antipodal cells contains one nucleus, totaling 3 nuclei.
- Each of the three synergid cells also contains one nucleus, totaling another 3 nuclei.
- The central cell contains two polar nuclei.
- Therefore, the total number of nuclei is:
- 3 (from antipodal) + 3 (from synergids) + 2 (from central cell) = 8 nuclei.

5. **Conclusion**:
- Based on the counts, the typical embryo sac of angiosperms is characterized as having 7 cells and 8 nuclei.

### Final Answer:
The typical embryo sac of angiosperms is **8 nucleated and 7 celled**.

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