Figure 5-1: General phage life cycle. Solid lines are paths that must be traversed to complete the phage life cycle while dashed lines are optional plus may be detrimental to phage propagation. I use the word 'Decay' in its most general sense to describe conversion of phage virions or intact phage-infected bacteria from a viable plaque-forming unit to either a non-infectious virion or a phage-infected bacterium that is unable to produce phage virions.