Gene Therapy: Core Concept Explained

Gene therapy is a medical approach that treats or prevents disease by modifying a person's genetic material.

Analyzing Gene Therapy Descriptions

Let's examine the options to find the best description of gene therapy:

1. Synthesis of DNA probes: Creating DNA probes is a laboratory technique used in molecular biology, often for detecting specific DNA sequences, but it's not the definition of gene therapy itself.
2. Mapping and isolation of gene sequence: These are crucial steps in genetic research and identifying genes, but they don't describe the therapeutic application of introducing genes.
3. Introduction of gene sequence into a cell: This directly describes the fundamental action of gene therapy – delivering genetic material into cells to correct a defect or provide a new function.
4. Use of polymerase chain reaction (PCR): PCR is a technique for amplifying DNA, widely used in diagnostics and research, but it's a tool, not the definition of gene therapy.

Conclusion on Gene Therapy

Gene therapy fundamentally involves introducing a specific gene sequence into a patient's cells. This corrected or functional gene can then help the body fight disease or produce necessary proteins.

Therefore, the introduction of a gene sequence into a cell is the most accurate description among the choices provided.