In the lysogenic cycle of a bacteriophage, which statement correctly describes the state of the phage genome with respect to the bacterial host?

Introduction / Context:Lysogeny is a dormant relationship between a bacteriophage and its bacterial host. Instead of producing new virions immediately, the phage genome becomes a prophage integrated into the host chromosome and is replicated with the host. This concept underpins lysogenic conversion and prophage induction.

Given Data / Assumptions:

• We focus on the state of the phage genome during lysogeny.
• No lytic replication occurs during stable maintenance.

Concept / Approach:In lysogeny, integration is mediated by phage integrase and host recombination systems. A repressor protein keeps lytic genes inactive. Environmental stress (e.g., DNA damage) can trigger induction to the lytic cycle.

Step-by-Step Solution:

Verification / Alternative check:Lambda phage lysogeny model (cI repressor, att sites) is the classic proof.

Why Other Options Are Wrong:

• Phage transfers bacterial DNA: That is generalized or specialized transduction, not lysogeny itself.
• Bacteria take up dsDNA from environment: Transformation, not lysogeny.
• Extracellular DNases stop the process: Relevant to transformation, not to integrated prophage maintenance.

Common Pitfalls:

• Mixing up transduction (DNA transfer by phage particles) with the dormancy of lysogeny.

Final Answer:A bacteriophage genome is integrated into the bacterial genome