Essentials of Genetics 9th Edition by Michael Palladino William Klug, Michael Cummings, Charlotte Spencer

Exercise 1

In this chapter, we have focused on genetic systems present in bacteria and the viruses that use bacteria as hosts (bacteriophages). In particular, we discussed mechanisms by which bacteria and their phages undergo genetic recombination, the basis of chromosome mapping. Based on your knowledge of these topics, answer several fundamental questions:
(a) How do we know that bacteria undergo genetic recombination, allowing the transfer of genes from one organism to another?
(b) How do we know that conjugation leading to genetic recombination between bacteria involves cell contact, which precedes the transfer of genes from one bacterium to another?
(c) How do we know that during transduction bacterial cell-to-cell contact is not essential?
(d) How do we know that intergenic exchange occurs in bacteriophages?