Bacteriophage one-step growth curve: The early interval after phage DNA injection during which no intracellular infectious phage can be recovered, even if cells are disrupted, is called the ______.

Introduction / Context:
In the classic one-step growth experiment, phage replication proceeds through definable phases. Correctly naming these phases is essential for interpreting kinetics, burst size, and intracellular events.

Given Data / Assumptions:

• Immediately after adsorption and genome injection, virions lose infectivity as particles and disassemble.
• No infectious phage can be detected inside cells by lysis during this interval.
• Later, progeny assemble and infectious particles reappear.

Concept / Approach:
The eclipse period spans the time from genome entry to the first appearance of mature, intracellular infectious phage. The latent period extends from infection to first extracellular release (lysis). The rise period is when extracellular phage count increases, and burst size is the number of virions released per infected cell.

Step-by-Step Solution:
Match the description “no recoverable infectious phage despite cell disruption” to the intracellular assembly gap.Identify this gap as the eclipse period.Exclude latent period (concerns extracellular detection) and rise period (release phase).

Verification / Alternative check:
Plot intracellular vs. extracellular infectivity over time; intracellular infectivity reappears before extracellular counts rise.

Why Other Options Are Wrong:
Latent period includes the eclipse but is defined by first release; rise period is the increase in extracellular phage; burst size is a value, not a time interval.

Common Pitfalls:
Confusing eclipse (intracellular undetectability) with latent (pre-release) because both occur before lysis.

Final Answer:
eclipse period