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

Options

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

Answer

To solve the question "The embryo sac formation is preceded by meiosis in:", we need to understand the process of embryo sac formation and the types of plants involved. Here’s a step-by-step breakdown:

### Step-by-Step Solution:

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

2. **Role of Meiosis**:
- Embryo sac formation begins with meiosis occurring in the megasporangium (ovule). The diploid megaspore mother cell undergoes meiosis to produce four haploid megaspores.

3. **Megaspore Development**:
- Out of the four megaspores produced, typically three degenerate, leaving one functional megaspore. This functional megaspore will develop into the embryo sac.

4. **Identifying the Types of Plants**:
- The question lists four organisms: Genetum, Triticum, Fucus, and Aphidra.
- **Triticum** (wheat) is an angiosperm, so it will undergo the process of embryo sac formation preceded by meiosis.
- **Genetum** is a gymnosperm, which also undergoes meiosis for embryo sac formation.
- **Fucus** is an alga and does not follow the same reproductive process as angiosperms or gymnosperms.
- **Aphidra** is also a gymnosperm.

5. **Conclusion**:
- The correct answer to the question is that embryo sac formation preceded by meiosis occurs in **Genetum, Triticum, and Aphidra**.

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

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