Arrange the following steps of genetically modifying an organism in the correct order.
I. Identification of DNA with desirable genes.
II. Transfer of the DNA to its progeny.
III. Maintenance of introduced DNA in the host.
IV. Introduction of identified DNA into the host.
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → I, IV, III and II
First – I. Identification of DNA with desirable genes. The gene that gives the wanted trait must be found before anything can be done with it.
Second – IV. Introduction of identified DNA into the host. The chosen DNA is then put into the host organism, usually with the help of a vector.
Third – III. Maintenance of introduced DNA in the host. The new DNA must stay and work inside the host cell. It can only be passed on if it is kept first.
Fourth – II. Transfer of the DNA to its progeny. Finally, the DNA is passed on to the offspring of the host. The book lists the last two steps together as its third step, in this order: maintenance first, then transfer.
NCERT Extract:
Principles of Biotechnology – “… The ability to multiply copies of antibiotic resistance gene in E. coli was called cloning of antibiotic resistance gene in E. coli. You can hence infer that there are three basic steps in genetically modifying an organism — (i) identification of DNA with desirable genes; (ii) introduction of the identified DNA into the host; (iii) maintenance of introduced DNA in the host and transfer of the DNA to its progeny.”