What is meant by gene therapy?

• A. Introduction of a healthy gene or replacement of a defective gene.
• B. Cloning of whole organisms.
• C. Sequencing of the genome.
• D. Editing metabolic pathways.

Answer: (A)

Gene therapy is about correcting genetic problems by introducing a healthy copy of a gene or replacing a defective one in a person's cells. The idea is to fix the root cause of a genetic disorder so the cell can produce the proper protein and restore normal function. This is typically achieved by delivering the therapeutic gene through vectors such as harmless viruses or by using gene-editing tools to fix the faulty gene directly. By supplying a functioning gene, the treatment aims to correct the underlying defect rather than just treating symptoms.

Cloning whole organisms is a different process focused on creating genetic twins of an organism. Sequencing the genome is a diagnostic or research activity that reads genetic information, not a treatment. Editing metabolic pathways describes changing how cellular processes work, which can be achieved through gene therapy but does not by itself define what gene therapy is—the defining feature is introducing or repairing genes to restore proper function.