Given below are names and recognition sequences of a few restriction enzymes that are used for cloning experiments. The cleavage site of each enzyme is indiceted by 

EcoRI-G'AATTC

HincII - GTY'RAC

EcoRV-GAT'ATC

BamHI-G 'GATCC

BglII-A 'GATCT

Given below are different vector (Column A) and insert (Column B) fragments generated by digestion using the above enzymes: 

Which one of the following options represents the correct combinations of the vector and insert, respectively, which generate compatible ends for ligation?​

Correct option is A

The question revolves around understanding the recognition sequences and cleavage sites of the given restriction enzymes, and matching vector fragments with insert fragments that create compatible cohesive ends for ligation.

• EcoRI recognizes G^AATTC, cutting between G and A, producing sticky ends.

• HincII recognizes GTY^RAC, cutting within the sequence, producing blunt ends.

• EcoRV recognizes GAT^ATC, producing blunt ends.

• BamHI recognizes G^GATCC, producing sticky ends.

• BglII recognizes A^GATCT, producing sticky ends compatible with BamHI ends.

The key to this problem is that fragments produced by enzymes that create compatible sticky ends can be ligated successfully.

• EcoRI sticky ends are compatible with EcoRI sticky ends only.

• BamHI and BglII generate compatible sticky ends (both generate 5' overhangs of GATC).

• HincII and EcoRV produce blunt ends, which can ligate with each other but less efficiently.

Looking at the options and the table:

• Option B pairs EcoRV (vector fragment) with HincII (insert fragment) - both blunt ends, compatible.

• D pairs BglII with BamHI - compatible sticky ends.

• E pairs HincII with BglII is incorrect because HincII produces blunt ends, and BglII sticky ends are not compatible with blunt ends.

• A pairs EcoRI with EcoRV (sticky with blunt) - not compatible.

• C pairs BamHI with EcoRI (sticky ends with different overhangs) - incompatible.

Therefore, option (b) is the only one with correct compatible ends.