Arrange the following steps of recombinant DNA technology in the correct order:
I. Extraction of the desired product
II. Fragmentation of DNA by restriction endonucleases
III. Isolation of a desired DNA fragment
IV. Ligation of the DNA fragment into a vector
V. Transferring the recombinant DNA into the host
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → II, III, IV, V, I
Recombinant DNA technology runs through its steps in a fixed order. After isolation of DNA, the steps in the list come as follows:
II. Fragmentation of DNA by restriction endonucleases — the isolated DNA is cut into fragments.
III. Isolation of a desired DNA fragment — the fragment carrying the gene of interest is separated from the rest.
IV. Ligation of the DNA fragment into a vector — the fragment is joined to the vector by DNA ligase, forming recombinant DNA.
V. Transferring the recombinant DNA into the host — the recombinant DNA enters the host cells, which are then cultured.
I. Extraction of the desired product — the product made by the cultured host cells is the last thing to be taken out.
So the correct order is II, III, IV, V, I.
NCERT Extract:
Processes of Recombinant DNA Technology – “Recombinant DNA technology involves several steps in specific sequence such as isolation of DNA, fragmentation of DNA by restriction endonucleases, isolation of a desired DNA fragment, ligation of the DNA fragment into a vector, transferring the recombinant DNA into the host, culturing the host cells in a medium at large scale and extraction of the desired product.”