For 10 points, name this group of viruses that infect bacteria.
A repressor found in one example of these entities binds to OR1, OR2, and OR3 and is a dimer named c1; that example expresses genes gam, red, xis, and int when its genome is transcribed leftward. One of these entities concatenates several copies of its genome, then cuts that structure into segments of the original length, forming circular permutations of the original sequence. That example cannot (*) integrate its genome into the host and instead must employ ribosomes until the host organism bursts. The T4 variety of this kind of virus employs the lytic cycle in infecting E. coli, as does the "lambda" variant. For 10 points, name this group of viruses that infect bacteria.
A repressor found in one example of these entities binds to OR1, OR2, and OR3 and is a dimer named c1; that example expresses genes gam, red, xis, and int when its genome is transcribed leftward.
bacteriophage