MCDB 2150 Fall 1998 Review Questions


Revised November 14, 1998

Lecture 30: PCR, knockout and transgenic organisms, biotechnology

1. The polymerase chain reaction (PCR) is a widely used technique in molecular genetics.

a. What special property must be possessed by the DNA polymerase used in PCR, and why is this so important for doing PCR?
b. Explain the use of primers in PCR, including why two different primers must be used.
c. What relationship must exist between the two primers used in PCR?
d. Summarize all of the components that must be present in a PCR reaction mixture.
e. Summarize the overall process that makes possible extensive amplification of specific DNA sequences with minimal effort through the use of PCR.

2. One of the ways of determining whether a sequence has been successfully amplified by PCR is to do electrophoresis and look for a band of DNA of sharply defined size. Explain how such a band arises during PCR.

3. Why is it not necessary to add new DNA polymerase and primers for each new cycle of PCR?

4. You have a cDNA of unknown sequence in a plasmid. How could you do a PCR amplification of the cDNA without first determining its end sequences?

5. What types of precautions must be taken when doing PCR to be certain that the desired results are obtained?

6. What aspects of PCR make it particularly useful in forensic investigations? How do the same properties make PCR particularly susceptible to challenge by defense lawyers?


Questions below this line will not be included on the fourth examination on November 18, 1998.

7. What are the essential features that must be included in a yeast artificial chromosome (YAC)?

8. What types of vectors are particularly useful for transformation of animal cells?

9. What types of vectors are particularly useful for transformation of plants?

10. How are transgenic mice generated?

11. Describe the various techniques that can be used to introduce a foreign DNA into a cell.

12. What is a knockout mouse and what is its special research value?

13. What is a reporter gene and what is it used for? Briefly describe threee commonly used reporter genes.

14. What type of genetic modification has been made in the Flavr Savr tomato? What is the market value of such a change?

15. What types of genetic diseases should be the most easily treated by genetic engineering?

16. What characteristics must a protein have to make it a practical candidate for commercial manufacture using recombinant DNA technology?

17. What are the practical reasons that often make it desirable to use an inducible promoter for commercial production of proteins from genetically engineered cells?

18. What problems make it impractical to produce some types of proteins using prokaryotic expression vector systems?

19. Cite an example of the spread of a human infectious disease by proteins derived from human sources that has been eliminated through the use of biotechnology. Identify both the protein and the disease.

20. Cite an example of a human genetic disease that has been successfully treated with gene therapy.

21. A substantial effort is being devoted to making certain kinds of plants resistant to herbicides such as glycophosphate.

a. What is the economic advantage of such a plant?
b. What procedures are being used?
c. What potential environmental concerns have been expressed about widespread use of such plants?

22. Describe the use of genetically engineered dairy animals for the production of non-milk proteins. What advantages does this procedure offer over alternative forms of biotechnology?

23. You have cloned a cDNA in a pBR322 vector. You now want to produce the protein coded by that cDNA in large amounts. What additional steps would be necessary?

24. What is an embryonal stem cell (ES cell) and what is its special value in genetic research?

25. Describe two different approaches that are being taking toward the use of biotechnology in vaccine production.

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