Final answer:
Phage λ can exhibit two growth modes: the lytic cycle, involving replication of phage DNA and host cell lysis to release new phage particles, and the lysogenic cycle, where phage DNA integrates into the host genome and can revert to the lytic cycle under stress. Mu phage also has these options plus the ability to transpose within the host genome.
Step-by-step explanation:
Modes of Growth for Bacteriophage λ (Lambda)
Phage λ, a temperate bacteriophage, can undergo two distinct growth pathways after infecting a bacterium: the lytic cycle and the lysogenic cycle. In the lytic cycle, phage DNA replicates independently within the host cell, commandeering the cell's machinery to produce new phage particles, which culminate in the host cell's lysis and the release of new phage particles into the environment. Contrastingly, in the lysogenic cycle, the phage DNA becomes integrated into the bacterial chromosome, effectively becoming a prophage. This integrated DNA can be replicated along with the host genome and transmitted to subsequent bacterial generations. Environmental triggers, such as starvation or exposure to toxic chemicals, may activate the prophage, leading it to excise itself from the bacterial chromosome and revert to the lytic cycle, producing new phage particles.
Mu phage, another bacteriophage, also displays these growth modes but adds a unique feature called transposition. After integrating into the bacterial chromosome, Mu phage can move about within the host genome. This transposition process provides Mu with an additional lifestyle choice beyond the lytic and lysogenic options.