MCB 229 Spring 2000 Study Guide 14 Prof. Terry
Covers Lecture for March 30

This study guide is intended for you to use while you are doing the assigned text reading. Quiz questions will be made with reference to topics in this study guide. Quiz #14, based on questions from this study guide, must be completed by midnight before the class on Thursday, March 30. You will need to create your "myWebCT" account and visit the MCB 229 WebCT page in order to access this quiz.

Chapter 13. Microbial genetics: general principles.
  1. What do each of the following terms mean: genome, haploid, diploid, genotype, phenotype?
  2. What discovery did Fred Griffith make? Alfred Hershey & Martha Chase?
  3. Material on pp. 258-262 was included in a previous study guide and will not be quizzed here, except as noted below.
  4. What do each of the following terms mean: mutation, conditional mutation, auxotroph, prototroph, mutagen, spontaneous mutation, induced mutation, transition mutation, transversion mutation, tautomeric shift, frameshift mutation?
  5. Can C ever form base pairs with A? If so, what is the mechanism? Can a purine ever base pair with a purine? A pyrimidine with a pyrmidine? If so, what is this called?
  6. Using the following DNA sequence as a template, practice making an appropriate base change to create each of the following:
    a transition mutant a transversion mutant a frameshift mutant
    ATTCAGACCA

    		 ATTCAGACCA

    		 ATTCAGACCA
  7. How does a base analog induce mutations? How does ethylmethanesulfonate (EMS) induce mutations? How do acridine dyes induce mutations? How does UV light induce mutations?
  8. What is meant by the following terms: wild type, forward mutation, reversion mutation, back mutation, suppressor mutation, point mutation, silent mutation, missense mutation, nonsense mutation?
  9. The study of mutants has been possibly the single most powerful tool in understanding the mechanics of life. Isolating a desired mutant is often challenging, however, because of the rarity of mutations. Spontaneous mutation frequencies in bacteria are roughly one per ______ cells; even with induced mutations the frequency is only about one per _______ cells. A number of ingenious schemes have been devised that select for certain types of mutants. The following questions address these selection strategems.
  10. What is replica plating? For what type of mutant selection is this useful?
  11. How would you isolate a bacterial mutant resistant to an antibotic? Resistant to a bacterial virus (phage)?
  12. What does the Ames test test for? What bacteria are used, and what properties do they have? Does the Ames test measure carcinogenicity? If not, what does it measure? What modification to the test is necessary in order to detect some carcinogens such as aflatoxins?
  13. What is excision repair? Roughly how many bases are removed during this proces? What enzymes are necessary for this process?
  14. What is photoreactivation? How does it differ from excision repair?
  15. How does recombination repair differ from excision repair? What is required in order for this system to work?
  16. What is SOS repair? Under what conditions is it active? How does it differ from excision repair?