Vector Biology Multiple Choice Questions on “Vectors for Mammals – 2”.
1. What is the main use of shuttle vectors consisting of BPV and E.coli sequences?
A. Pharming
B. Gene therapy
A. Recombinant protein production
D. Recombinant DNA
Answer: C
Clarification: Shuttle vectors consisting of E.coli and BPV sequences are capable of replication in both mouse and bacterial cells and are hence used for recombinant protein production in mouse cell lines.
2. What is the similarity between AAV and Adenovirus?
A. Size
B. Host cell location
A. Host tissue location
D. Infection mechanism
Answer: C
Clarification: Adeno-associated virus which is unrelated to adenovirus but often found in the same infected tissues. AAV makes use of some proteins found in Adenovirus.
3. Which is the helper virus in an AAV?
A. Baculovirus
B. Adenovirus
A. Papillomavirus
D. Retrovirus
Answer: B
Clarification: AAV is found in the same infected tissues as Adenovirus because it makes use of some of the proteins synthesized by the adenovirus in order to complete its replication cycle.
4. Which of the following unusual property is associated with an Adeno-associated virus?
A. Always inserting at the same position
B. Always inserting at different position
A. Always falling short for integration
D. Jumping gene property
Answer: A
Clarification: In the absence of helper Adenovirus, the Adeno-associated virus genome inserts it into host’s DNA. With most integrative viruses this is a random event but AAV always inserts itself at the same position.
5. Which is the particular site of insertion of AAV?
A. Chromosome 4
B. Chromosome 5
A. Chromosome 9
D. Chromosome 19
Answer: D
Clarification: With most integrative viruses this is a random event but AAV always inserts itself at the same position, within human chromosome 19.
6. The most common use of Retroviruses is _________
A. Pharming
B. Gene therapy
A. Recombinant protein production
D. Molecular cloning
Answer: B
Clarification: Retroviruses are the most common vectors for gene therapy. Although they insert at random positions, the resulting integrants are very stable.
7. The resulting integrants of Retroviruses are unstable.
A. True
B. False
Answer: B
Clarification: Although they insert at random positions, the resulting integrants are very stable, which means that therapeutic effects of a cloned gene will persist for longer.
8. Microinjection is a process of transferring genes into _________ cells.
A. Mammalian
B. Plant
A. Yeast
D. Bacterial
Answer: A
Clarification: One of the reasons why viral vectors have not yet become widespread in mammalian gene cloning is because it was discovered in the early 1990s that the most effective way is microinjection.
9. Why is microinjection more satisfactory than using a viral vector for mammalian cells?
A. Compatibility
B. Ease of cloning
A. Avoiding infection and defects
D. Wide host range
Answer: C
Clarification: The procedure of microinjection is more satisfactory in that the use of a viral vector because it avoids the possibility that viral DNA will infect the cells and cause defects of one kind or the other.
10. What is a chimera mouse?
A. Comprising a mix of cloned and natural cells
B. Comprising a mix of cloned cells
A. Comprising only natural cells
D. Comprising tumorigenic cells