Question

How are sticky ends produced ? Mention their role.

Assertion (A) : Restriction endonuclease recognises palindromic sequence in DNA and cuts them. Reason (R) : Palindromic sequence has two unique recognition sites PstI and PvuI recognised by restriction endonuclease.

(a) Write the palindromic nucleotide sequence for following sequence of DNA segment : 5' – GAATTC – 3' (b) Name the restriction endonuclease that recognizes this sequence. (c) How are sticky ends produced ? Mention their role.

(a) Explain the importance of 'ori' and 'rop' in the E. coli cloning vector shown in the above given diagram. (b) Differentiate between exonucleases and endonucleases.