Palindromic DNA implies-

Ans. is 'a' i.e., Sho stretches of DNA; 'b' i.e., Recognised by specific restriction endonuclease; c i.e., Complementary strands Palindromic DNA o A DNA sequence consists of two complementry strand coiled in a double helicle structure. o A sequence of duplex DNA that is same when two strands are read in opposite direction is called Palindrome 5'-GGCC-3' 3'-CCGG-5' Figure 1 - Palindrome o These palindrome serves as the target for most restriction endonuclease. Also know Inveed repeats o In these cases, two different segments of the double helix read in the same but in opposite direction. 5' - AGAACA nnnnnnnnn TGTTCT - 3' 3' - TCTTGT nnnnnnnnn ACAAGA - 5' Figure 2 - Inveed repeats Now you must be thinking that what is the difference between palindrome and inveed repeats ? o In palindrome the sequence is same in the complementry region of two strands, ie. the strands of DNA have same sequence in opposite direction on the same segment (see fig 1) of DNA. o In inveed repeats it occurs on two different segments of DNA, i.e. it is not complementry. The intervening strands of DNA do not have same sequence in opposite direction (see fig 2).