Genetics: Analysis and Principles 5th Edition by Robert Brooker

Exercise 41

This question combines your knowledge of conjugation (described in Chapter 7) and the genetic regulation that directs the phage reproductive cycles. When researchers mix donor Hfr strains with recipient F bacteria that are lysogenic for phage , the conjugated cells survive normally. However, if donor Hfr strains that are lysogenic for phage conjugate with recipient F bacteria that do not contain any phage , the recipient cells often lyse, due to the induction of into the lytic cycle. Based on your knowledge of the regulation of the two cycles, explain this experimental observation.