Temperate phages — When prophage DNA excises from the host chromosome and the phage enters the lytic cycle, the process is called:

Introduction:
Induction is the switch from lysogeny to the lytic cycle in temperate bacteriophages. The term distinguishes how the prophage is activated to replicate and lyse the cell.

Given Data / Assumptions:

• Prophage DNA can excise from the chromosome.
• Entry into the lytic cycle follows excision.
• If no external trigger is specified, the baseline term is spontaneous induction.

Concept / Approach:
Induction can be triggered by DNA damage (e.g., UV), chemicals, or occur at low frequency without external stimuli. The latter is termed spontaneous induction and reflects stochastic loss of repression or cellular stress fluctuations.

Step-by-Step Solution:

Verification / Alternative check:
Lambda phage literature routinely uses spontaneous induction to describe prophage activation events in the absence of deliberate inducers.

Why Other Options Are Wrong:

• Inductive infection: nonstandard term.
• Resultant induction: nonstandard term.
• Spontaneous infection: describes infection, not prophage activation.

Common Pitfalls:
Confusing induction with lysogenization, which is the establishment of lysogeny.

Final Answer:
Spontaneous induction