Name_____________________________________ Student No.______________

Please write the letters corresponding to your answers in the spaces provided.

1.____________ 2.__________ 3. __________ 4.___________5.__________

6. ___________ 7. __________ 8. __________ 9. __________ 10. __________

The first eight questions on this problem set require you to use the virtual fly lab. Starting from the course home page, click on virtual fly lab, read the information on the course page about using the virtual fly lab, and then click on the link to the virtual fly lab itself.

Questions 1-5: The first five questions require you to use the virtual fly lab to determine the mode of inheritance for five different mutations in Drosophila. Please note that the abbreviations from the virtual fly lab, which are employed in these questions do not provide any information about the mode of inheritance. For each of these questions, the possible answers are.

A. Autosomal recessive
B. Sex-linked recessive
C. Autosomal Dominant but not lethal when homozygous
D. Autosomal Dominant and lethal when homozygous
E. Sex-linked Dominant

1. Tan body (T)

2. Apterous wings (AP)

3. Bar eyes (B)

4. Lobe eyes (L)

5. Aristapedia antennae (AR)

6. Which two of the three autosomal loci in questions 1-5 are on the same chromosome? Write their one or two letter abbreviations in the space for an answer to question 6. (Hints: In order to do a test cross, you need all of the recessive alleles in the same parent. For dominant mutations, wild-type is the recessive allele. Also, you want ot avoid recombination when you are looking for linkage. It is therefore helpful to make the male the heterozygous partner in the test cross. Also, be sure to remember that the dominant lethal is heterozygous in the original parent. Avoid any crosses where the results might be distorted by dominant lethality.)

7. The following autosomal recessives are all on the same large chromosome: ebony body (E), incomplete (radius incompleus) wing veins (RI), and spineless bristles (SS). Which of the following combines the correct gene order and the approximate map distance between the two outside loci? (Hint: Remember that recombination occurs only in female Drosophila. Also, keep in mind that each run of the virtual fly lab will generate slightly different results. Thus, you are looking for the closest match to your results.)

A. RI, SS, E, 21.8 map units.
B. RI, E, SS, 19.2 map units.
C. SS, E, RI, 21.8 map units
D. E, RI, SS, 10.5 map units
E. RI, SS, E, 19.2 map units.

8. Three of the following autosomal recessive markers are on the same chromosome, but may be very distant from one another. Black body (BL), Dumpy wings (DP), Shaven bristles (SV), Incomplete (radius incompletus) wing veins (RI), and Brown eyes (BW) . Which three are on the same chromosome? (Hint: recombination can make distantly linked markers look like they are not linked. Design your crosses to avoid that trap.)

A. BL, DP, BW;
B. BL, RI, BW
C. DP, RI, BW
D. SV, DP, BW
E. BL, SV, BW

9. Complementation between two different mutant strains usually means:

A. That the two mutations are identical in all respects.
B. That both mutant strains are heterozygous.
C. That genetic recombination has occurred.
D. That each mutation has resulted in loss of function of a different polypeptide.
E. That both mutations are in the coding sequence for the same protein.

10. Hfr strains of bacteria exhibit which of the following properties?

A. They are genetically unstable with a high frequency of reorganization of their own genomes.
B. They have F⁺ plasmids integrated into their genomes, which causes them to initiate genetic transfer of bacterial genes to F^- strains frequently.
C. They serve very readily as recipients for genetic transfers from other bacterial cells.
D. They exchange genes readily with other Hfr cells.
E. They are stable merozygotes with partial duplication of the bacterial genome.