Which of the following sequences lists the steps of genetic engineering in the correct order?

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

Answer: (D)

The sequence tests understanding of the flow from obtaining the gene to producing a product. You start by isolating the gene of interest from donor DNA, because you need the specific sequence you want to work with. Next, you cut both the gene fragment and the vector so their ends are compatible, allowing the gene to be inserted into the vector. Then you introduce the recombinant DNA into host cells through transformation, which is the step that gets the engineered DNA inside a living system where it can be used. After that, you consider introducing the new base sequence changes to ensure the construct has the correct sequence and regulatory elements for expression. Finally, you achieve expression, where the host cells read the gene and produce the desired product. This ordering makes sense because you must build the recombinant DNA first, then get it into a host, ensure it’s properly configured, and only then drive production of the target product.