quizzes

quizzes - Discussion Section quizzes-Second half of LS4...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
Discussion Section quizzes—Second half of LS4 Complementation Testing 1) Four rII- recessive point mutations were discovered. Coinfections of bacteria with all possible combinations of rII- mutant T4 phages were performed, and the following results were obtained. Fill in the chart 1 2 3 4 1 - 2 - 3 - 4 - How many genes are identified by this analysis? ______________ Which mutants belong to the same complementation groups? 2) 1. You have two mutant organisms expressing the same phenotype and want to know whether the mutations are in the same gene. What type of test can you do to determine this? ______________________________ 2. What do you need to determine before you can do the test listed for question 1?
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
3. If you cross the two mutant organisms from question 1 and get a wild type phenotype, are the mutations in the same gene or different genes? 4. Are the two mutations from question 3 in the same complementation group? 5. Can point mutations spontaneously revert to wild type? Can deletions spontaneously revert to wild type? 3) (1) What is the purpose of a complementation test? (2) What is one criterion the mutations in question must fit in order for a complementation test to be a valid experiment? (3) Why are complementation tests more straightforward in most eukaryotes than in bacteria or viruses? (4) Is this an example of complementation or of failure to complement? 4) A) You are a geneticist working with T4 phage and have discovered an interesting mutation that slows the rate at which the phage is able to produce plaques on a lawn of E. coli. You have been able to isolate 2 strains of phage that show this phenyotype. You wish to know if the strains have mutations in the same or different genes, so you perform a complementation study. Upon co-infection you see the mutant phenotype, i.e. slow growing plaques. Based on this study alone, would you conclude that the mutations are in the same gene or in two different genes? B) To confirm your results you decide to send out the strains genomic DNA for sequencing. The sequencing results reveal that the mutations are in different genes. Is this consistent with your complementation study results? If not, indicate why this might be the case.
Background image of page 2
5) You have 3 turtles, each with a mutation that causes them to have a strange polka dotted pattern on their shells. You don’t know if the mutations are the in the same gene or in different genes. Assume that all 3 mutations are homozygous recessive. a) Which crosses would you set up to find out if the mutations are in the same gene or in different genes? b) You discover that turtle1 and turtle3 have mutations in the same gene, while turtle1 and turtle 2 have mutations in different genes. What phenotype would you expect from crosses between: Turtle3 x turtle2 Turtle1 x turtle3 6) It’s a very well known fact that most dragons do not breathe fire, and it’s also well known that alleles that enable fire breathing are recessive to the wild-type Sweet Breath
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 07/14/2008 for the course LS 4 taught by Professor Ribaya during the Fall '08 term at UCLA.

Page1 / 11

quizzes - Discussion Section quizzes-Second half of LS4...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online