Gene therapy has been successful in curing genetic diseases in laboratory animals through

Options

A. Exposure to X-ray to rectify the defective gene
B. Replacing the defective gene with a functional gene
C. Oral delivery of genes
D. Use of therapeutic medicines to rectify the defective genes

Answer

**Step-by-Step Solution:**

1. **Understanding Gene Therapy**: Gene therapy is a technique that involves modifying or manipulating genes to treat or prevent diseases. It aims to correct defective genes responsible for disease development.

2. **Identifying the Options**: The question provides four options regarding how gene therapy has been successful in curing genetic diseases in laboratory animals:
- A) Exposure to X-ray to rectify the defective gene
- B) Replacing the defective gene with a functional gene
- C) Oral delivery of gene
- D) Use of therapeutic medicines to rectify the defective genes

3. **Evaluating Each Option**:
- **Option A**: Exposure to X-ray is not a method of gene therapy; it is typically used for other medical treatments, such as cancer.
- **Option B**: Replacing the defective gene with a functional gene is a core principle of gene therapy. This method directly addresses the root cause of genetic diseases by substituting the faulty gene with a healthy one.
- **Option C**: Oral delivery of gene is not a standard method for gene therapy, as genes are usually delivered through vectors like viruses or liposomes.
- **Option D**: Use of therapeutic medicines to rectify defective genes does not align with the definition of gene therapy, which focuses on genetic modification rather than pharmaceutical intervention.

4. **Conclusion**: Based on the evaluation, the most accurate option that describes how gene therapy has been successful in curing genetic diseases in laboratory animals is:
- **B) Replacing the defective gene with a functional gene**.

**Final Answer**: Gene therapy has been successful in curing genetic diseases in laboratory animals through replacing the defective gene with a functional gene.

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