Question

The basic scheme of the essential steps involved in the process of recombinant DNA technology is summarised below in the form of a flow diagram. Study the given flow diagram and answer the questions that follow.

(a) What is the technical term used for Step 4 in the above process?
(b) Which of the given two combinations of restriction enzyme should be used in Step 1? Justify your answer. 
(i) EcoR I to cut the plasmid and Hind III to cut the alien DNA. 
(ii) EcoR I to cut both the plasmid and alien DNA.

Hint:

Cloning is the term for replicating recombinant DNA. Always use the same restriction enzyme on both vector and insert to produce compatible sticky ends.

Answer 1

(a) Step 1: Step 4 involves producing multiple copies of the recombinant DNA.
Step 2: The correct technical term for this process is cloning. 
Step 3: Cloning allows amplification of the gene of interest inside the host cell. 
(b) Step 1: To ligate both vector and foreign DNA, compatible ends are required. 
Step 2: If different enzymes (like EcoR I and Hind III) are used, the ends will not match and ligation will be unsuccessful. 
Step 3: Therefore, the correct option is (ii): EcoR I to cut both the plasmid and alien DNA. 
Step 4: Using the same restriction enzyme ensures that both DNA fragments have complementary sticky ends that can easily join.