Out of linear tetrad wich one is the functional megaspore

Options

A. Micropylar
B. Any of the middle ones
C. Chalazal
D. Any of the four.

Answer

To determine which megaspore is functional out of a linear tetrad, we need to understand the arrangement and functionality of megaspores produced from the megaspore mother cell (MMC).

### Step-by-Step Solution:

1. **Understanding Megaspores**:
- Megaspores are produced from the megaspore mother cell (MMC) through the process of meiosis. This results in four haploid megaspores.

2. **Arrangement of Megaspores**:
- These four megaspores are arranged in a linear tetrad. The arrangement typically consists of four megaspores aligned in a straight line.

3. **Identifying Functional Megaspores**:
- In most flowering plants, out of the four megaspores produced, usually only one becomes functional while the others degenerate.

4. **Types of Functional Megaspores**:
- The functional megaspore can vary depending on the plant species. In many cases, the chalazal megaspore (the one closest to the chalaza) is the functional one. However, in some species like Onothera, the micropilar megaspores can also be functional.

5. **Conclusion**:
- Given that the question asks about the linear tetrad and based on the most common occurrence in plants, the chalazal megaspore is typically the functional megaspore.

### Final Answer:
The functional megaspore in a linear tetrad is the **chalazal megaspore**.

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