Q.The process of recombinant DNA technology has the following steps
I. amplication of the gene
II. Insertion of recombinant DNA into the host cells
III. Cutting of DNA at specific location using restriction enzyme .
IV. Isolation of genetic material (DNA)
Pick out the correct sequence of step for recombinant DNA technology.
a. II, III, IV, I
b. IV, II, III, I
c. I, II, III, IV
d. IV, III, I, II

Step 1. Identify what must happen first. Nothing can be cut, amplified or inserted before the genetic material carrying the gene of interest has actually been isolated - so 'Isolation of genetic material (DNA)' (IV) must be the first step.

Step 2. Identify what happens to isolated DNA next. Once DNA is isolated, the gene of interest still has to be physically excised from it at defined points - this is 'Cutting of DNA at specific location using restriction enzyme' (III), which logically follows isolation.

Step 3. Identify what happens before insertion into a host. After the gene fragment has been cut out, the chapter describes that the desired gene can be multiplied by PCR before being delivered into a host cell - this is 'amplification of the gene' (I), which makes sense as the step that generates enough copies of the fragment to work with before committing to insertion. …

Reconstruct the logical dependency between the four steps (you cannot cut before isolating, amplify before cutting, or insert before amplifyi …

• Assuming amplification must come after insertion into the host cell, rather than recognising PCR-based amplification of the excised gene as a pre-insertion step. …