Main steps in the formation of Recombinant DNA are given below. Arrange these steps in a correct sequence.A. Insertion of recombinant DNA into the host cell.B. Cutting of DNA at specific location by restriction enzyme.C. Isolation of desired DNA frag…

Answer: 2. B, C, D, A or 4. C, B, D, A

Key idea: A recombinant DNA is made by cutting the DNA, getting the desired fragment, amplifying it, and finally putting it into a host cell.

1. The source DNA is cut with a restriction enzyme (B) and the desired fragment is isolated (C). These two steps can be done in either order: isolate the fragment and then cut it to the required ends, or cut first and then separate the fragment of interest.
2. The gene of interest is amplified by PCR (D) to get many copies.
3. The recombinant DNA is inserted into the host cell (A).

So both C, B, D, A (option 4) and B, C, D, A (option 2) are acceptable, and the official key lists both. Options 1 and 3 put insertion (A) before amplification or cutting, which is not possible.