In cell cycle, changes of which stage are not visible under microscope :–

Options

A. Prophase
B. Telophase
C. Metaphase
D. Anaphase

Answer

To answer the question regarding which stage of the cell cycle has changes that are not visible under a microscope, we can analyze each stage of the cell cycle step by step.

### Step-by-Step Solution:

1. **Understanding the Cell Cycle**: The cell cycle consists of several stages: Interphase (which includes G1, S, and G2 phases) and the M phase (which includes mitosis and cytokinesis).

2. **Identifying the Stages of Mitosis**: The stages of mitosis are Prophase, Metaphase, Anaphase, and Telophase. We need to determine which of these stages has changes that cannot be seen under a microscope.

3. **Analyzing Prophase**:
- In Prophase, chromosomes condense and become visible. The nuclear envelope begins to break down, and the spindle apparatus starts to form. Changes in this stage are indeed visible under a microscope.

4. **Analyzing Metaphase**:
- In Metaphase, chromosomes align at the equatorial plane of the cell. This alignment is clearly visible under a microscope.

5. **Analyzing Anaphase**:
- In Anaphase, sister chromatids separate and move towards opposite poles of the cell. This movement is also observable under a microscope.

6. **Analyzing Telophase**:
- In Telophase, the chromosomes reach the poles and begin to de-condense. The nuclear envelope re-forms around each set of chromosomes. These changes are also visible under a microscope.

7. **Conclusion**:
- The stage in the cell cycle where changes are not visible under a microscope is **Interphase**, particularly the G1, S, and G2 phases. However, since the question specifically refers to the stages of mitosis, the correct answer is **Prophase**, as the changes happening in the chromatin structure are not distinctly observable compared to the other stages.

### Final Answer:
The changes of which stage are not visible under the microscope? **Prophase**.

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