CHALLENGE QUESTION

Section 7.2

Question 25

25.A group of genetics students mix two auxotrophic strains of bacteria: one is leu+ trp+ his met and the other is leu trp his+ met+. After mixing the two strains, they plate the bacteria on minimal medium and observe a few prototrophic colonies (leu+ trp+ his+ met+). They assume that some gene transfer has taken place between the two strains. How can they determine whether the transfer of genes is due to conjugation, transduction, or transformation?