Open QuestionFor bacteria that are F⁺, Hfr, F', and F⁻ perform or answer the following.Describe the results of conjugation (i.e., changes in the recipient and the exconjugant) that allow detection of the state of the F factor in a donor strain.
Open QuestionFor bacteria that are F⁺, Hfr, F', and F⁻ perform or answer the following.Which of these donors can transfer a donor gene to exconjugants?
Open QuestionFor bacteria that are F⁺, Hfr, F', and F⁻ perform or answer the following.Which of these donors can convert exconjugants to a donor state?
Open QuestionFor bacteria that are F⁺, Hfr, F', and F⁻ perform or answer the following.Which of these cells are donors? Which is the recipient?
Open QuestionIn this chapter, we have focused on genetic systems present in bacteria and on the viruses that use bacteria as hosts (bacteriophages). In particular, we discussed mechanisms by which bacteria and their phages undergo genetic recombination, which allows geneticists to map bacterial and bacteriophage chromosomes. In the process, we found many opportunities to consider how this information was acquired. From the explanations given in the chapter, what answers would you propose to the following questions?How do we know whether or not genetic recombination between bacteria involves cell-to-cell contact?
Open QuestionThe flow diagram identifies relationships between bacterial strains in various F factor states. For each of the four arrows in the diagram, provide a description of the events involved in the transition.
Open QuestionConjugation between an Hfr cell and an F⁻ cell does not usually result in conversion of exconjugants to the donor state. Occasionally, however, the result of this conjugation is two Hfr cells. Explain how this occurs.
Open QuestionWith respect to F⁺ and F⁻ bacterial matings, answer the following questions:What is the genetic basis for a bacterium's being F⁺.