Question: 170: Given Below are two statements:
Statement I:
Restriction endonucleases recognise specific sequence to cut DNA known as palindromic nucleotide sequence.
Statement II:
Restriction endonucleases cut the DNA strand a little away from the centre of the palindromic site.
In the light of the above statements, choose the most appropriate answer from the options given below:
(1) Statement I is correct but Statement II is incorrect
(2) Statement I is incorrect but Statement II is correct
(3) Both Statement I and Statement II are correct
(4) Both Statement I and Statement II are incorrect
Answer: Option (3)
Explanation:
Restriction endonucleases are enzymes that recognise specific DNA sequences
and cleave the DNA at or near these sites.
These specific recognition sequences are called palindromic nucleotide sequences because
the sequence reads the same in the 5' \rightarrow 3' direction on both strands.
Thus, Statement I is correct.
Restriction endonucleases usually cut the DNA strands slightly away from
the centre of the palindromic sequence, producing either sticky ends or blunt ends.
This makes Statement II also correct.
Therefore, both Statement I and Statement II are correct.