Assertion :- Kinetochore is essential for cell division.
Reason:- Kinetochores serve as the sites of attachment of spindle fibres to the chromosome.

Options

A. If both Assertion & Reason are True & the Reason is a correct explanation of the Assertion.
B. If both Assertion & Reason are True but Reason is not a correct explanation of the Assertion
C. If Assertion is True but the Reason is False
D. If both Assertion & Reason are false.

Answer

To solve the question, we need to analyze both the assertion and the reason provided.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "Kinetochore is essential for cell division."
- This is true because kinetochores play a critical role during cell division by ensuring that chromosomes are properly segregated into the daughter cells.

2. **Understanding the Reason**:
- The reason states that "Kinetochores serve as the sites of attachment of spindle fibres to the chromosome."
- This is also true. Kinetochores are specialized protein structures on the chromosome where the spindle fibers attach during cell division, facilitating the movement of chromosomes.

3. **Evaluating the Relationship**:
- Since both the assertion and the reason are true, we need to determine if the reason correctly explains the assertion.
- The reason does indeed explain why the kinetochore is essential for cell division: it provides the attachment point for spindle fibers, which is necessary for the proper segregation of chromosomes.

4. **Conclusion**:
- Both the assertion and the reason are true, and the reason is the correct explanation of the assertion. Therefore, the correct answer is that both the assertion and reason are true, and the reason is the correct explanation of the assertion.

### Final Answer:
- The correct answer is **Option 1**: Both assertion and reason are true, and the reason is the correct explanation of the assertion.

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