The functional megaspore in Capsella is always

Options

A. Micropylar
B. Chalazal
C. All the above
D. Any of the four

Answer

To answer the question regarding the functional megaspore in Capsella, we can break down the solution into the following steps:

### Step-by-Step Solution:

1. **Understanding Megaspores**: The process begins with the megaspore mother cell (megasporangium) undergoing meiosis. This results in the formation of four haploid megaspores.

2. **Arrangement of Megaspores**: These four megaspores are arranged in a linear tetrad. This means they are aligned in a straight line, which is a characteristic of the megasporogenesis process.

3. **Functional Megaspore**: Out of the four megaspores formed, only one remains functional and develops into the female gametophyte (embryo sac). The other three megaspores degenerate and do not contribute to the gametophyte formation.

4. **Location of Functional Megaspore**: The functional megaspore can be located either at the micropylar end or the chalazal end of the ovule, depending on the species.

5. **Specifics for Capsella**: In the case of Capsella, it is important to note that the functional megaspore can be either micropylar or chalazal. However, in many angiosperms, including Capsella, the functional megaspore is typically found at the chalazal end.

6. **Conclusion**: Therefore, the correct answer to the question is that the functional megaspore in Capsella is always chalazal.

### Final Answer:
The functional megaspore in Capsella is always chalazal.

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