Observe the diagram and answer the question.

A transformed E. coli colony with the above shown vector can grow in ampicillin containing media but not on tetracycline containing media. The probable site where forgein DNA got inserted in the vector would be:

(A) Hind III
(B) BamH I
(C) Pvu I
(D) Pvu II

Choose the correct answer from the options given below:

(B) Only

The correct answer is Option (2) → (B) Only

In many cloning vectors (like the common pBR322 plasmid), there are antibiotic resistance genes for both ampicillin and tetracycline. The ampicillin resistance gene (Amp^r) allows the colony to grow in media containing ampicillin, while the tetracycline resistance gene (Tet^r) allows growth in media containing tetracycline.

When foreign DNA is inserted into the BamH I site within the tetracycline resistance gene (Tet^r), it disrupts this gene. As a result:

• The ampicillin resistance remains intact, allowing the transformed colony to grow on ampicillin-containing media.
• The tetracycline resistance is disrupted, so the colony cannot grow on tetracycline-containing media.

Since the transformed E. coli colony can grow on ampicillin but not on tetracycline, this indicates that the foreign DNA likely inserted at the BamH I site within the tetracycline resistance gene.

So, the correct answer is: BamH I

 E. coli cloning vector pBR322 showing restriction sites (Hind III, EcoR I, BamH I, Sal I, Pvu II, Pst I, Cla I), ori and antibiotic resistance genes (ampR and tetR). rop codes for the proteins involved in the replication of the plasmid.