The embryo sac formation is preceded by meiosis in `:`

Options

A. Gnetum
B. Triticum
C. Fucus
D. Ephedra

Answer

To answer the question "The embryo sac formation is preceded by meiosis in:", we need to analyze the options provided and understand the process of embryo sac formation in plants.

### Step-by-Step Solution:

1. **Understanding Embryo Sac Formation**:
- The embryo sac is the female gametophyte in angiosperms (flowering plants).
- It is formed within the ovule, which is located in the ovary of the pistil.

2. **Process of Formation**:
- The formation of the embryo sac begins with a diploid megasporangium (the mother cell).
- This megasporangium undergoes meiosis to produce four haploid megaspores.
- Out of these four megaspores, typically three degenerate, leaving one functional megaspore.
- This functional megaspore then undergoes mitotic divisions to form the embryo sac.

3. **Analyzing the Options**:
- **Genetum**: This is a gymnosperm. Gymnosperms do not form an embryo sac; instead, they have a different reproductive structure. Thus, this option is incorrect.
- **Triticum**: This is the scientific name for wheat, which is an angiosperm. In angiosperms, the embryo sac formation is indeed preceded by meiosis. Therefore, this option is correct.
- **Fucus**: This is an algae. Algae do not produce embryo sacs as they do not have the same reproductive structures as flowering plants. Thus, this option is incorrect.
- **Ephedra**: This is another gymnosperm. Similar to Genetum, it does not form an embryo sac. Thus, this option is also incorrect.

4. **Conclusion**:
- Based on the analysis, the correct answer is **Triticum**, as it is the only option where embryo sac formation is preceded by meiosis.

### Final Answer:
The embryo sac formation is preceded by meiosis in **Triticum**.

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