Given below are two statements. 
One is labelled as Assertion (A) and the other is labelled as Reason (R). 
Assertion (A) : When a particular restriction enzyme cuts a strand of DNA, overhanging stretches or sticky ends are formed.  
Reason (R) : Some restriction enzymes cut the strand of DNA a little away from the centre of the palindromic site.  
In the light of the above statements, choose the correct answer from the options given below.

Assertion (A) is correct. Restriction enzymes are enzymes that recognise specific DNA sequences called recognition sites or palindromic sequences. When a restriction enzyme cuts DNA, it cleaves the phosphodiester backbone of both strands at specific positions within or near the recognition site. Depending on the specific restriction enzyme, the cuts can be made symmetrically or asymmetrically. 

Symmetric cuts result in blunt ends, where the DNA fragments have no overhangs. The two ends of the DNA fragment are precisely aligned with each other.

Asymmetric cuts result in overhanging stretches of single-stranded DNA at the ends of the DNA fragments. These overhanging stretches are called sticky ends because they have complementary base sequences, which can form hydrogen bond with each other when exposed to a DNA fragment cut by the same restriction enzyme. 

Reason (R) is also correct. Palindromic sequences are sequences of DNA that read the same on both strands when read in the 5’ to 3’ direction. For example, the palindromic DNA sequence 5’-GAATTC-3’ reads the same on both strands as 5’-GAATTC-3’. 

Restriction enzymes recognise and bind to these palindromic sequences, and some restriction enzymes cut the DNA at positions that are not directly in the centre of the palindromic site. As a result, the cuts may occur a little away from the centre, leading to the formation of sticky ends with singlestranded overhangs.

Both (A) and (R) are correct and (R) is the correct explanation of (A).