Which practice involves introducing healthy genes into a living organism to treat a disease?

• A. Recombinant DNA
• B. Genetic testing
• C. Cloning
• D. Gene Therapy

Answer: (D)

Introducing healthy genes into a living organism to treat a disease is gene therapy. The goal is to provide a normal copy of a gene or edit a faulty one so cells can function properly and disease symptoms are reduced or eliminated. This is usually done by delivering the therapeutic gene into the patient’s cells using vectors such as modified viruses or other delivery methods, sometimes even directly editing the genome to correct mutations. This differs from recombinant DNA, which is a lab technique for assembling DNA from different sources and is a tool used in research and therapy development rather than a treatment applied to a patient by itself. Genetic testing screens for mutations but does not change them, and cloning creates genetically identical copies rather than treating disease in a patient. Gene therapy best fits the description.