You must work independently. You may, however, request assistance from the instructor. You may also, if you are enrolled in the appropriate class, get help from the Humanities Center or similar tutorial assistance to improve the written presentation. The intent here is that you are responsible for the content.

Please try to focus your answers as much as possible. Aim for brief & complete. Remember that answers that do not relate to the question may cost credit for errors, but can not earn any credit since they do not answer the question!! Thus, it is to your advantage torefrain from adding extraneous information. Please do NOT just copy from a book. Note that often a book is not answering precisely the question that you are supposed to be addressing!

1. We have discussed three mechanisms by which bacteria can acquire foreign DNA. Identify and describe these three mechanisms, showing how they differ. Detail how each is used by geneticists. Give at least one example of how genetic exchange such as this (in general - by any mechanism) may be important in nature.

2. Describe the lac and the trp operon. In both cases, two distinct and different regulatory mechanisms (note: do not just describe one mechanism turned on or off) must be described. Explain how the regulation of these two operons are integrated with the organism's needs and physiology; briefly compare and contrast the two systems.  

3. Complete the chart below. How is this system used to demonstrate trans-dominance? cis-dominance? Explain what these terms mean and show how the phenomena can be illustrated [if necessary, add appropriate experiments to the chart]. Briefly explain the interpretation of these data by noting what can be inferred from each experiment. Which are controls - and controls for what? What controls are required to demonstrate each phenomenon? [one way to answer this last part is to list which experiments, as a separate group, could be used to demonstrate each characteristic]. BE CAREFUL - NO CREDIT WILL BE GIVEN FOR REVERSED LINES! 

5. Describe for yourself an imaginary prokaryote capable of E. coli - like Hfr conjugation. Construct data from which one could infer a genetic map of your organism - at least 6 gene, on a chromosome at leastthree times as long as Hfr can transfer in a single event - from Hfr conjugation. Data should be presented in an orderly manner. Be sure to state the phenotypes of the F⁺ and F^- original strains as well as the phenotypes of the Hfr conjugates after different times of conjugation. Then analyze your own data to (re-) generate the map. Explain the logic of this analysis. 

6. Describe three things you saw at the lab field trip that interested you, and what you learned from them. 

7. The following DNA sequence is a fragment of a much longer piece: 

5'G-T-T-T-C-A-T-C-G-T-T-C-A-C-A-T-C-G-A-A-G-T-G-T-C-C-A-T-T-G-A-3'strand 1

3'C-A-A-A-G-T-A-G-C-A-A-G-T-G-T-A-G-C-T-T-C-A-C-A-G-G-T-A-A-C-T-5'strand 2 

a. If this DNA codes for a polypeptide, which is the template strand?

b. Write the mRNA sequence that would be transcribed. 

c. Write the polypeptide that would be translated.  

d. If the G-C indicated above were mutated to a T-A, what polypeptide would be translated? 

e. If, INSTEAD, a T-A were inserted at the indicated above, what polypeptide would be translated? 

f. If, INSTEAD, the A-T indicated above were deleted, what polypeptide would be translated? 

g. (e) and (f), but not (d), are examples of what sort of mutation (what characteristic do they have in common, which differs from (d))? 

BONUS [5 pt] What question were you expecting that was not asked? Write your own question & answer it. Credit will depend on value of question as well as answer. Note: since this is a take-home, standards for awarding points will be high.