Question

Which vector is commonly used in gene therapy?

• A. Yeast artificial chromosome
• B. Viral vectors
• C. Cosmids
• D. Plasmids only

Hint:

Remember the most common gene therapy vectors:
• Adenovirus
• Adeno-associated virus (AAV)
• Retrovirus
• Lentivirus These modified viruses efficiently deliver therapeutic genes into human cells.

Answer 1

The Correct Option is B

Concept: Gene therapy is a technique used to treat or prevent genetic diseases by introducing a functional gene into the patient's cells. To deliver the therapeutic gene safely and efficiently, special carriers called vectors are used. The most commonly used vectors are modified viruses because they naturally possess the ability to enter host cells.
• Viral vectors efficiently transfer genes into target cells.
• Disease-causing viral genes are removed before use.
• The therapeutic gene is inserted into the viral genome.
• Viral vectors provide high gene transfer efficiency and stable expression.

Step 1: Understand viral vectors.
Viruses naturally infect cells by introducing their genetic material. Scientists modify viruses by:
• Removing pathogenic genes.
• Inserting the desired therapeutic gene.
• Allowing the virus to act only as a delivery vehicle. \[ \boxed{\text{Modified Virus} \longrightarrow \text{Delivers Therapeutic Gene}} \]

Step 2: Examples of viral vectors.
Common viral vectors include:
• Adenovirus
• Adeno-associated virus (AAV)
• Retrovirus
• Lentivirus These vectors efficiently introduce genes into dividing or non-dividing cells depending on the vector type.

Step 3: Eliminate the incorrect options.

• Yeast artificial chromosomes are mainly research cloning vectors.
• Cosmids are cloning vectors used in molecular biology.
• Plasmids are useful in laboratory cloning but are much less efficient for clinical gene therapy.
• Viral vectors are the standard delivery system used in most gene therapy applications. Therefore, \[ \boxed{Option (B) is the correct answer. \]