Select the incorrect statement .

Options

A. The nucleus of the functional megaspore divides mitotically to form two nuclei which move to the opposite poles, forming the 2-nucleate embryo sac.
B. Two more sequential mitotic nuclear divisions result in the formation of the 4-nucleate and later the 8-nucleate stages of the embryo sac.
C. Six of the eight nuclei are surrounded by cell walls and organised into cells.
D. The two nuclei, called polar nuclei are situated above the egg apparatus in the large central cell.

Answer

To solve the question of identifying the incorrect statement regarding the development of the female gametophyte (embryo sac) in plants, we can analyze each statement step by step:

### Step-by-Step Solution:

1. **Analyze the First Statement:**
- The statement claims that the nucleus of the functional megaspore divides mitotically to form two nuclei, which then move to opposite poles, forming a two-nucleate embryo sac.
- **Evaluation:** This statement is correct. The functional megaspore undergoes mitotic division, leading to the formation of two nuclei that migrate to opposite ends.

**Hint:** Check if the process of mitotic division and movement of nuclei is accurately described.

2. **Analyze the Second Statement:**
- This statement mentions that two sequential mitotic nuclear divisions result in the formation of 4-nucleate and later 8-nucleate stages of the embryo sac.
- **Evaluation:** This statement is also correct. After the initial division, the two nuclei further divide to form 4 nuclei, and then these divide again to form 8 nuclei.

**Hint:** Consider the sequence of mitotic divisions and the resulting number of nuclei.

3. **Analyze the Third Statement:**
- The statement asserts that 6 of the 8 nuclei are surrounded by cell walls and organized into cells.
- **Evaluation:** This statement is correct. In the embryo sac, 6 of the 8 nuclei indeed become surrounded by cell walls and organize into distinct cells.

**Hint:** Recall how nuclei are organized in the embryo sac and the number of cells formed.

4. **Analyze the Fourth Statement:**
- The statement claims that the two nuclei called polar nuclei are situated above the egg apparatus in the large central cell.
- **Evaluation:** This statement is incorrect. The polar nuclei are actually located below the egg apparatus within the large central cell.

**Hint:** Visualize the structure of the embryo sac and the positioning of the polar nuclei relative to the egg apparatus.

### Conclusion:
The incorrect statement is the fourth one, which misplaces the location of the polar nuclei in relation to the egg apparatus.

### Final Answer:
**The incorrect statement is:** "The two nuclei called polar nuclei are situated above the egg apparatus in the large central cell."