Assertion :- For long DNA molecule, the two strnds of DNA can not be separated in it's entire length.
Reason: It needs very high energy investment

Options

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

Answer

**Step-by-Step Solution:**

1. **Understanding the Assertion**: The assertion states that for a long DNA molecule, the two strands cannot be separated along its entire length. This is true because DNA is a long molecule, often several meters in length when fully extended, and the strands are held together by hydrogen bonds between complementary bases (adenine with thymine and cytosine with guanine).

2. **Analyzing the Reason**: The reason provided states that separating the two strands of DNA requires a very high energy investment. This is also true, as breaking the hydrogen bonds that hold the strands together does require energy, typically in the form of ATP.

3. **Connecting Assertion and Reason**: The assertion is true because the long DNA strands cannot be separated entirely due to the stability provided by the hydrogen bonds. The reason is also true because breaking these bonds does require a significant amount of energy. Therefore, the reason explains why the assertion is true.

4. **Conclusion**: Since both the assertion and the reason are true, and the reason correctly explains the assertion, we conclude that the correct answer is that both the assertion and the reason are true, and the reason is the correct explanation of the assertion.

**Final Answer**: Option A - Both assertion and reason are true, and reason is the correct explanation of assertion.

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