Two different T4 rll mutants are used to co-infect E. coli strain K(). Lysis was extremely rare and only a few progeny phage were produced. What does this tell you? *[strain K(lambda), in case the lambda symbol does not show on your device] The two mutants could not recombine. The two mutants both carried mutations in the same rll gene. The mutants cannot inject their DNA into this host. One of the mutants was a double mutant..