What best describes recombinant DNA?

• A. DNA that has been polymerized
• B. DNA that replicates itself easily
• C. DNA that can cause a disease when given to an animal
• D. DNA that has been created in the laboratory

Answer: (D)

Recombinant DNA is DNA that has been created in the laboratory by joining genetic material from different sources into one molecule. This human-directed assembly typically uses enzymes to cut and paste DNA fragments and often places the combined DNA into a vector like a plasmid so it can be propagated and, if desired, expressed in a host organism. This lab-made, combined DNA distinguishes it from natural DNA that simply polymerizes or replicates on its own, or DNA that is inherently disease-causing without being engineered. An example is inserting a human gene into bacteria to produce a therapeutic protein, illustrating how recombinant DNA is deliberately constructed in the lab.