Question

Genetic engineering involves the following steps
A. Gene manipulation and vector construction
B. Selection and confirmation of the transformants
C. Gene isolation
D. Genetic transformation
What is the correct sequence in which these steps are performed?

• A. B, A, D, C
• B. A, D, C, B
• C. D, B, C, A
• D. C, A, D, B

Hint:

The standard recombinant DNA workflow follows a logical sequence:
Isolate the gene (C) $\rightarrow$ Construct the recombinant vector (A) $\rightarrow$ Transform the host (D) $\rightarrow$ Select and confirm transformants (B).

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Genetic engineering, or recombinant DNA technology, involves a series of steps to isolate, modify, and introduce a target gene into a host organism to express a desired trait.

Step 2: Detailed Explanation:
The logical sequence of steps in a genetic engineering workflow is as follows:
1. C. Gene isolation: The first step is to identify and isolate the gene of interest from the donor organism's genomic DNA using techniques like PCR, restriction digestion, or cDNA library screening.
2. A. Gene manipulation and vector construction: The isolated gene is cloned into a suitable vector (such as a plasmid) alongside appropriate regulatory elements (promoters and terminators) to create a recombinant DNA molecule.
3. D. Genetic transformation: The constructed recombinant vector is introduced into host cells (such as plant tissue or bacterial cells) using methods like Agrobacterium-mediated transformation or biolistics (gene gun).
4. B. Selection and confirmation of the transformants: The transformed cells are grown on selective media containing antibiotic or herbicide agents to eliminate non-transformants.
The presence and expression of the transgene are subsequently confirmed using molecular assays like PCR, Southern blotting, or RT-qPCR.
This sequence of steps corresponds to C $\rightarrow$ A $\rightarrow$ D $\rightarrow$ B.

Step 3: Final Answer:
The correct sequence of steps in genetic engineering is C, A, D, B, which corresponds to Option (D).