Central cell of embryo sac contains

Options

A. A single haploid nucleus
B. Two haploid polar nucleus
C. One diploid fusion or secondary nucleus
D. Either B or C.

Answer

To answer the question regarding what the central cell of the embryo sac contains, we can break down the information step by step:

### Step-by-Step Solution:

1. **Understanding the Structure of the Embryo Sac**:
- The embryo sac is formed from a functional megasporangium through a series of mitotic divisions. Initially, a single megaspor undergoes mitosis to form multiple cells.

2. **Formation of the Central Cell**:
- During the development of the embryo sac, the megaspor undergoes mitotic divisions without cytokinesis, leading to the formation of eight nuclei. These nuclei organize into specific groups.
- Out of these eight nuclei, three migrate towards the chalazal end (these are called antipodals), while three move towards the micropylar end to form the egg apparatus (which includes the egg cell and synergids).

3. **Identifying the Central Cell**:
- The central cell is formed by the fusion of two polar nuclei, which are located in the center of the embryo sac. This is a crucial point because it distinguishes the central cell from other cells in the embryo sac.

4. **Determining the Nucleus Type**:
- The central cell contains two haploid polar nuclei, which together create a diploid structure. This is often referred to as the secondary nucleus or diploid fusion nucleus.

5. **Conclusion**:
- Therefore, the central cell of the embryo sac contains two haploid polar nuclei, which can also be described as one diploid fusion nucleus (secondary nucleus).

### Final Answer:
The central cell of the embryo sac contains **two haploid polar nuclei** (Option 2) or can be referred to as **one diploid fusion nucleus** (Option 3).

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