Name 7 03 Exam Three 2005 Name Exam starts at 11 05 am and ends at 11 55 am There are 8 pages including this cover page Please write your name on each page Only writing on the FRONT of every page will be graded You may use the backs but only as scratch paper Question 1 17 pts Question 2 45 pts Question 3 20 pts Question 4 18 pts TOTAL out of 100 1 Name 1 17 pts You are studying the expression of the yeast gene ProA that is necessary for the synthesis of the amino acid proline ProA is normally expressed only when the cell is lacking supplemental proline in the growth medium You isolate two haploid yeast strains ProB and ProC that misregulate ProA expression You mate a ProB haploid strain to a wild type haploid strain The resulting diploid expresses ProA properly You mate a ProB haploid strain to a ProA haploid strain The resulting diploid expresses ProA properly You mate a ProA ProC haploid strain to a ProC haploid strain The resulting diploid expresses ProA when proline is present in the growth medium You mate a ProC haploid strain to a ProA haploid strain The resulting diploid expresses ProA properly You mate a ProB ProC haploid strain to a wild type haploid strain The resulting diploid expresses ProA properly You induce sporulation of this diploid and examine 40 tetrads 30 of those 40 each contain two spores that do not express ProA when proline is absent from the growth medium one spore that expresses ProA when proline is present in the growth medium and one spore that expresses ProA properly a 6pts Classify the ProB mutation by its genetic properties cis vs trans constitutive vs uninducible dominant vs recessive b 6pts Classify the ProC mutation by its genetic properties cis vs trans constitutive vs uninducible dominant vs recessive c 5pts If you a drew a linear pathway showing the regulation of ProA which function would you place closer to ProA ProB or ProC 2 Name 2 45 pts You are studying the transcriptional regulation of a mouse gene called Stringy This gene is normally only expressed in tail cells due to the presence of a tailspecific inducer molecule in these cells You have isolated two true breeding mutant strains of mice that do not spatially regulate the expression of the Stringy gene properly The strains of mice that you have and their corresponding phenotypes are listed in the table below Genotype of mouse Wild type A A B B Phenotype of mouse Stringy expressed only in tail Stringy not expressed anywhere Stringy expressed in all cells in the body When you cross mice that are B B to mice that are deficient in Stringy the resulting mice only have Stringy expressed in the tail When you cross mice that are B B to mice that are A A and then cross the resulting F1 mice to each other you get a genotypic ratio in the F2 that indicates that the A and B loci segregate independently of each other You inject a piece of DNA containing the A allele of the A gene into a fertilized egg produced by the mating of two true breeding B mice You then transfer this injected fertilized egg into a pseudopregnant mouse The mouse that is born does not express Stringy in any cells in its body a 6pts Classify the A mutation by its genetic properties cis vs trans constitutive vs uninducible dominant vs recessive b 6pts Classify the B mutation by its genetic properties cis vs trans constitutive vs uninducible dominant vs recessive 3 Name c 12pts Draw TWO different linear genetic pathways that are consistent with your answers to parts a and b Be sure to indicate the wild type A B and Stringy genes in your model and also include the tail specific inducer molecule d 6pts Clearly state which one piece of information you would need to know in order to determine which of the models you drew in part c was correct 4 Name e 15pts You want to distinguish between the two models listed in part c You could do this by creating a genetically engineered mouse For the mouse you make please state i whether you are using pronuclear injection or gene targeting ii what DNA you would introduce into the mouse cells also draw the DNA iii what is the genotype of the fertilized egg or the ES cells you would start with iv which additional breeding steps you would do to make the mouse you wanted v two possible phenotypic results you could get from the newly made mice and the corresponding conclusion you would make for each result Describe a way to create a genetically modified mouse that would allow you to gain the piece of information you stated in part d and thereby distinguish between your models i ii iii iv v 5 Name 3 20 pts For each situation below predict whether the frequency of the ALLELE q associated with the trait disorder in consideration will stay the same rise or fall If you cannot conclude choose inconclusive For parts a b and c assume that the mutation rate is zero a 5pts There is a population in which a rare autosomal recessive trait with S 0 h 0 exists This population always mates randomly All of a sudden heterozygotes obtain a selective advantage The allele frequency q will CIRCLE ONE OF THE FOUR stay the same rise inconclusive fall b 5pts There is a population in which a rare autosomal recessive disorder with S 1 h 0 exists All of a sudden this population goes from mating randomly to participating in some amount of inbreeding The allele frequency q will CIRCLE ONE OF THE FOUR stay the same rise inconclusive fall c 5pts There is a population in which a rare autosomal dominant trait with S 0 h 0 exists All of a sudden this population goes from mating randomly to participating in some amount of inbreeding The allele frequency q will CIRCLE ONE OF THE FOUR stay the same rise inconclusive fall d 5pts There is a population in which a rare autosomal recessive disorder with S 1 h 0 exists All of a sudden this population goes from mating randomly to participating in some amount of inbreeding Simultaneously the mutation rate rises from being negligible to a rate that would now affect allele frequency The allele frequency q will CIRCLE ONE OF THE FOUR stay the same rise inconclusive fall 6 Name 4 18 pts 6 Consider a gene in which mutations occur at a rate of 10 Mutations in this gene will cause an autosomal recessive disease Homozygotes for the allele associated with the disease have a fitness which is 10 that of those not carrying that allele SHOW ALL OF YOUR WORK indicate all equations you use and use clear labels Note If you need the quadratic formula it is 2 b b 4ac 2a a 6pts Assume that for many generations
View Full Document
Unlocking...