Question

In gene therapy using stem cells, viruses are mainly used as vectors because they:

• A. Help in inserting the active gene into stem cells.
• B. Destroy the defective gene in defective cells.
• C. Increase the number of stem cells in the body.
• D. Convert body cells into stem cells.

Hint:

Viruses are used in gene therapy because they naturally deliver DNA into host cells.

Answer 1

The Correct Option is A

Step 1: Understanding gene therapy.
Gene therapy involves introducing a functional gene into cells to replace or repair a defective gene responsible for a disease.
Step 2: Role of vectors.
Vectors are carriers that help transfer the desired gene into target cells. Viruses are commonly used as vectors because of their natural ability to enter cells and deliver genetic material.
Step 3: Function of viruses in gene therapy.
Modified viruses are engineered so that they are harmless but can still carry and insert the required gene into the host cell's DNA. This helps in correcting genetic defects.
Step 4: Analysis of options.
(a) Correct — Viruses insert the desired gene into stem cells.
(b) Incorrect — Viruses do not directly destroy defective genes.
(c) Incorrect — They do not increase stem cell numbers.
(d) Incorrect — They do not convert body cells into stem cells.
Step 5: Conclusion.
Thus, viruses are used because they help in inserting the active gene into stem cells.