Chromosomes are in their most extended form during:

Options

A. interphase
B. anaphase
C. metaphase
D. prophase

Answer

To determine when chromosomes are in their most extended form, we need to analyze the different phases of the cell cycle and the characteristics of chromosomes during these phases.

### Step-by-Step Solution:

1. **Understanding Chromatin and Chromosomes**:
- Chromatin is the relaxed form of DNA found in the nucleus during interphase. It is less condensed and allows for gene expression and DNA replication.

2. **Identifying the Phases**:
- The question provides four phases:
- Interphase
- Anaphase
- Metaphase
- Prophase

3. **Analyzing Each Phase**:
- **Interphase**: During this phase, chromatin is in its most extended form. The DNA is not tightly packed, allowing for transcription and replication.
- **Anaphase**: In this phase, chromosomes are pulled apart towards opposite poles of the cell. They are more condensed but not in their extended form.
- **Metaphase**: Here, chromosomes are aligned at the equatorial plate of the cell. They are still condensed and not in their extended form.
- **Prophase**: During prophase, chromosomes become visible as they condense and the nuclear membrane begins to break down. They are not in their extended form at this stage.

4. **Conclusion**:
- The phase in which chromosomes are in their most extended form is **Interphase**. This is when chromatin is relaxed and spread throughout the nucleus.

### Final Answer:
**Chromosomes are in their most extended form during Interphase.**