BIO 301, Genetics - Spring 2000
Review 2 Translation, Mutations, Molecular Genetics
Provide thorough, but concise, answers to 7 of the 8
There is no time limit to this test, but it should not take you more than 2 hours to complete.
The review is closed book.
Calculators are permitted.
All questions are worth 20 points.
If your handwriting is lousy, please type your answers.
Staple all pages together and do not put your name on any page other than this cover page.
Return completed review to me no later than 10:30am, Wednesday, April 19, 2000.
Name (please print):
Pledge and signature:
Answer 7 of the 8 questions
4. Four Hfr strains are used to map E. coli genes. Through a series of interrupted conjugation experiments, it is observed that these Hfr strains donate the following genes to the recipient cell in the orders shown:
Strain 1 - Q W D M T
Strain 2 - A X P T M
Strain 3 - B N C A X
Strain 4 - B Q W D M
What is the order of these genes on the chromosome of E. coli? What feature of the E. coli chromosome is illustrated by these results? How do Hfr bacterial strains differ from F+ strains?
5. For the following lac operon partial diploids, explain which genes will be expressed in the presence and absence of lactose. NOTE: A (-) next to a gene indicates that a mutation exists in that gene that precludes expression.
A. I-O+Z+Y+A+ / I+O+Z+Y+A+
B. IsO+Z-Y+A+ / I-O+Z+Y-A+
C. I+OcZ+Y-A+ / I-O+Z-Y+A+
D. I-OcZ-Y-A+ / I+O+Z+Y+A+
6. It is known that the enzyme wildcatase is abundant in the liver of humans. How would you construct a genomic DNA library and then screen this library to identify the clone containing the wildcatase gene? Provide two different means of generating a specific probe.
7. Members of your laboratory group have cloned the wildcatase cDNA and inserted it into a prokaryotic expression vector. But your advisor isnt satisfied. She wants to be able to regulate the expression of wildcatase in transformed bacteria (in other words, be able to turn on and off expression). You are asked to design a new plasmid that will allow regulated expression of wildcatase. Describe this new plasmid. Will it work in any E. coli or will it only function properly in certain strains of E. coli? Why?
8. Describe the important genetic features of an insertion sequence. Describe the important genetic features of a transposon. In what ways are retroviruses similar to transposable elements? What evidence exists suggesting that integrated retroviruses may move within the human genome?