Assertion: Polytene chromosomes have a high amount of DNA.
Reason: Polytene chromosomes are formed by repeated replication of chromosomal DNA without separation of chromatids

Options

A. Both Assertion & Reason are true and the reason is the correct explanation of the assertion.
B. Both Assertion & Reason are true but the reason is not the correct explanation of the assertion.
C. Assertion is true statement but Reason is false.
D. Both Assertion and Reason are false statements.

Explanation

To solve the question regarding the assertion and reason about polytene chromosomes, we will break it down step by step.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "Polytene chromosomes have a high amount of DNA."
- Polytene chromosomes are indeed known to have a high amount of DNA because they are formed from multiple rounds of DNA replication without cell division.

**Hint**: Consider what polytene chromosomes are and how they differ from typical chromosomes in terms of DNA content.

2. **Understanding the Reason**:
- The reason provided is "Polytene chromosomes are formed by repeated replication of chromosomal DNA without separation of chromatids."
- This statement is accurate. Polytene chromosomes arise from a process called endomitosis or endoreduplication, where DNA replicates multiple times without the subsequent separation of chromatids.

**Hint**: Reflect on the process of how polytene chromosomes are formed and the significance of the lack of separation of chromatids.

3. **Evaluating the Relationship**:
- Now we need to assess whether the reason correctly explains the assertion.
- Since the formation of polytene chromosomes (as described in the reason) directly leads to their high DNA content (as stated in the assertion), the reason does indeed provide a correct explanation for the assertion.

**Hint**: Think about how the formation process of polytene chromosomes directly contributes to their characteristics.

4. **Conclusion**:
- Both the assertion and the reason are true, and the reason correctly explains 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.

**Hint**: Look for options that indicate both statements are true and that one explains the other.

### Final Answer:
Both assertion and reason are true, and the reason is the correct explanation of the assertion.