Which of the following sequences correctly lists the genetic engineering steps?

• A. Isolation, Cutting, Transformation, Introduction to new base sequence changes, Expression
• B. Introduction to new base sequence changes, Expression, Isolation, Cutting, Transformation
• C. Cutting, Isolation, Transformation, Expression, Introduction to new base sequence changes
• D. Isolation, Transformation, Cutting, Introduction to new base sequence changes, Expression

Answer: (A)

The main idea here is the logical flow of building and using recombinant DNA: obtain the gene, prepare it, get it into a host, tweak the construct if needed, and then produce the protein. You start by isolating the gene of interest from the donor DNA so you have the actual sequence to work with. Next, you cut the DNA to create compatible ends that can be joined to a vector, forming recombinant DNA. Then you introduce this recombinant DNA into host cells through transformation so the construct can be maintained and propagated. After the DNA is inside the host, you can make any necessary base-sequence changes to optimize the construct for expression (such as adding regulatory elements or tags). Finally, with the construct in place and properly regulated, the gene is expressed to produce the desired protein. This order reflects the progression from building the genetic material to achieving expression, matching the typical workflow.