The ploidy level of secondary nucleus of embryosac is :-

Options

A. 2n
B. 3n
C. 4n
D. 5n

Answer

To determine the ploidy level of the secondary nucleus of the embryo sac, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Structure of the Embryo Sac**:
The embryo sac is a structure within the ovule that contains several cells. It typically consists of seven cells arranged in a specific manner.

2. **Identifying the Cells in the Embryo Sac**:
The embryo sac contains:
- One egg cell
- Two synergids (helper cells)
- Three antipodal cells
- One central cell (which contains the secondary nucleus)

3. **Ploidy Level of the Cells**:
- The egg cell, synergids, and antipodal cells are all haploid (N).
- The central cell, which is the focus of the question, is formed by the fusion of two polar nuclei.

4. **Formation of the Secondary Nucleus**:
The secondary nucleus is formed when the two polar nuclei within the central cell fuse together. This fusion results in a diploid nucleus.

5. **Conclusion**:
Therefore, the ploidy level of the secondary nucleus of the embryo sac is 2N (diploid).

### Final Answer:
The ploidy level of the secondary nucleus of the embryo sac is **2N**.

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