Question

The following diagram represents a restriction enzyme site:
Statement I: After digestion cohesive ends will be formed.
Statement II: These cohesive ends will have phosphate groups at 3' and 5' ends.

• A. Both Statement I and Statement II are correct
• B. Both Statement I and Statement II are incorrect
• C. Statement I is correct but Statement II is incorrect
• D. Statement I is incorrect but Statement II is correct

Hint:

Staggered cuts = Sticky/Cohesive ends. Standard cuts = 5'-P and 3'-OH.

Answer 1

The Correct Option is C

Step 1: Concept
Restriction enzymes cut DNA at specific palindromic sequences, creating either blunt or sticky (cohesive) ends.

Step 2: Meaning
Cohesive ends are overhanging single-stranded regions.

Step 3: Analysis
The staggered cut shown in the diagram creates 5' single-stranded overhangs, which are cohesive ends, making Statement I correct. However, a standard restriction cut leaves a 5'-phosphate and a 3'-hydroxyl group; it does not leave phosphate groups at both ends, making Statement II incorrect.

Step 4: Conclusion
Only the first statement regarding the formation of cohesive ends is accurate. Final Answer: (C)