This set of Vector Biology Multiple Choice Questions & Answers (MCQs) focuses on “Vectors for Mammals – 2”.
1. What is the main use of shuttle vectors consisting of BPV and E.coli sequences?
b) Gene therapy
c) Recombinant protein production
d) Recombinant DNA
Explanation: 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?
b) Host cell location
c) Host tissue location
d) Infection mechanism
Explanation: 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?
Explanation: 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
c) Always falling short for integration
d) Jumping gene property
Explanation: 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
c) Chromosome 9
d) Chromosome 19
Explanation: 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 _________
b) Gene therapy
c) Recombinant protein production
d) Molecular cloning
Explanation: 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.
Explanation: 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.
Explanation: 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?
b) Ease of cloning
c) Avoiding infection and defects
d) Wide host range
Explanation: 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
c) Comprising only natural cells
d) Comprising tumorigenic cells
Explanation: After microinjection, the ES cells are placed in the embryo which is implanted into the foster mother. The resulting mouse is a chimera, which comprises a mixture of engineered and non-engineered cells.
11. A transgenic animal is the one that contains cloned genes in a few of its cells.
Explanation: Microinjection is the basis to create a transgenic animal, one that contains a cloned gene in all of its cells. A mouse is an example.
12. What are embryonic stem cells?
a) Pluripotent cells
b) Multipotent cells
c) Totipotent cells
d) Cells from transgenic mice
Explanation: Embryonic stem cells are obtained from within an early embryo and are totipotent, meaning that their developmental pattern is not present.
13. Non chimeric mice contain _________ in all their cells.
a) Totipotent cells
b) ES cells
c) Non-engineered cells
d) Cloned genes
Explanation: Non-chimeric mice, which contain the cloned gene in all their cells, are obtained by allowing the chimera to reproduce, as some of the offspring will be derived from egg cells that contain the cloned gene.
14. In transgenic animals, what is a foster mother?
a) From which ES cells are derived
b) From which embryo is derived
c) Into which embryo is implanted
d) Whose genes are used
Explanation: A transgenic mouse is generated by microinjection of a fertilized egg cell which is subsequently cultured in vitro for several cell divisions and then implanted into the foster mother.
15. Therapeutic effects of the cloned gene using which of the following vector will persist for longer?
Explanation: Retroviruses are the most common vectors used for gene therapy and they produce very stable integrants in the host cells, hence their effects on cloned genes persist for longer.
Sanfoundry Global Education & Learning Series – Vector Biology & Gene Manipulation.
To practice all areas of Vector Biology & Gene Manipulation, here is complete set of 1000+ Multiple Choice Questions and Answers.