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Assertion : Three main types of restrict...

Assertion : Three main types of restriction endonucleases i.e., Type I, Type II and Type III are known with slightly different mode of action.
Reason: In palindromes with rotational symmetry second half of complementary strand in DNA double helix is the mirror image of base sequence in the first half of another strand.

A

If both Assertion and Reason are true and Reason is a correct explanation of the Assertion.

B

If both Assertion and Reason are true but Reason is not a correct explanation of the Assertion.

C

If Assertion is true but Reason is false.

D

If both Assertion and Reason are false.

Text Solution

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The correct Answer is:
**Step-by-Step Solution:** 1. **Understanding the Assertion**: The assertion states that there are three main types of restriction endonucleases: Type I, Type II, and Type III, which have slightly different modes of action. This is true as each type of restriction enzyme has unique characteristics in terms of their recognition sites and cutting mechanisms. 2. **Understanding the Reason**: The reason provided explains that in palindromic sequences, the second half of the complementary strand in a DNA double helix is a mirror image of the base sequence in the first half of another strand. This is also true, as palindromic sequences have the property that they read the same forwards and backwards on complementary strands. 3. **Analyzing the Relationship**: While both the assertion and the reason are true, the reason does not directly explain why there are three types of restriction endonucleases. The assertion is about the classification of restriction enzymes, while the reason describes a characteristic of palindromic sequences that these enzymes recognize. 4. **Conclusion**: Since both the assertion and the reason are true but the reason does not serve as a correct explanation for the assertion, the correct answer is that both are true, but the reason is not the correct explanation for the assertion. **Final Answer**: Both assertion and reason are true, but the reason is not the correct explanation for the assertion. ---
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Restriction endonuclease was isolated for the first time by W. Aber in 1962 in bacteria. Restriction endonucleases cut the DNA duplex at specific points therefore they are also called as molecular scissors or biological scissors. Three types of restriction endemicleases are Type 1. Type II and Type III but only Type II restriction endonucleases are used in recombinant DNA technology. Restriction endonuclease EcoR I recognises the base sequence GAATTC In DNA duplex and cut strands between G and A. Which type of restriction endonucleases is used most in genetic engineering?

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Restriction endonuclease was isolated for the first time by W. Aber in 1962 in bacteria. Restriction endonucleases cut the DNA duplex at specific points therefore they are also called as molecular scissors or biological scissors. Three types of restriction endemicleases are Type 1. Type II and Type III but only Type II restriction endonucleases are used in recombinant DNA technology. Restriction endonuclease EcoR I recognises the base sequence GAATTC In DNA duplex and cut strands between G and A. Only type II restriction enzymes are used in gene manipulation because:

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