Selection Of Recombinant Transformants

In recombinant DNA technology antibiotics are used:

1. to keep medium bacteria-free

2. to detect alien DNA

3. to impart disease-resistance to the host plant

4. as selectable markers

The blue and white selectable markers have been developed which differentiate recombinant colonies from non-recombinant colonies on the basis of their ability to produce colour in the presence of a chromogenic substrate.
Given below are two statements about this method:

Statement I:	The blue coloured colonies have DNA insert in the plasmid and they are identified as recombinant colonies.
Statement II:	The colonies without blue colour have DNA insert in the plasmid and are identified as recombinant colonies.

1.	Statement I is correct; Statement II is incorrect
2.	Statement I is incorrect; Statement II is correct
3.	Both Statement I and Statement II are correct
4.	Both Statement I and Statement II are incorrect