AP BIOLOGY

Detailed explanation-1: -Many restriction enzymes or restriction endonucleases identify a specific palindrome site and cut the DNA strands. They mostly cut the DNA, slightly away from the centre of the palindrome and between the same two nitrogenous bases in both the strands.

Detailed explanation-2: -Restriction enzymes cut double-stranded DNA * at specific locations based the pattern of bases found at those locations. These enzymes predictably cut both strands because the sequences they recognize are palindromic. That is the recognition sequences are short string of identical bases on both DNA strands.

Detailed explanation-3: -A palindromic sequence is the same backwards and forwards on both sides (see image below). This means that the enzyme recognizes the sequence no matter from which side the enzyme approaches the DNA. A palindromic sequence also increases the chance that both strands of DNA are cut.

Detailed explanation-4: -Type IIQ restriction enzymes cleave DNA symmetrically within their recognition sequence, which differs by one base pair from a palindrome.

Detailed explanation-5: -The site recognized by a restriction enzyme to cleave DNA is called a recognition site. These sites are located on a DNA molecule containing specific sequences of nucleotide (4-8 base pair)