The correct answer is Option (3) → (B), (A), (D), (C)
(B) Isolation and cutting of DNA at specific locations
(A) Joining of foreign DNA to plasmid
(D) Insertion of rDNA or ligated DNA into the host cell/organism
(C) Obtaining the foreign gene product
The correct sequence of steps in recombinant DNA technology is as follows:
- Isolation of the genetic material (DNA) – The first step is to isolate the DNA containing the desired gene.
- Cutting of source DNA as well as vector DNA at specific location and their joining – The source DNA and vector DNA are cut using restriction enzymes and then joined to create recombinant DNA.A vector is a carrier DNA molecule used to transfer the gene of interest into the host organism. In this step, the isolated DNA fragment (gene of interest) is inserted into the vector DNA using the enzyme DNA ligase, which joins the two DNA molecules together.
- Insertion of recombinant DNA into the host/ organism: After the DNA fragment is ligated into the vector, the recombinant DNA is ready for transfer into the host organism, such as bacteria, plant cells, or animal cells. This transfer is usually achieved through transformation methods specific to the host organism, such as electroporation or biolistics.
- Culturing transformed host cells at large scale – The host cells containing recombinant DNA are cultured on a large scale to increase the yield.
- Obtaining the foreign gene product – Once the recombinant DNA is successfully transferred into the host, the host cells begin to produce the desired gene product, such as a protein or enzyme encoded by the gene of interest. The gene product is then extracted and purified for various applications, such as medical treatments, biotechnology, or research.
By following these steps, scientists can manipulate DNA to introduce specific genes into different organisms, leading to the production of desired gene products with various applications in medicine, agriculture, and industry. |
