Life Sciences 11 · Biology · Lesson 3.2
The lytic & lysogenic cycles
- Level
- Grade 11
- Reading time
- 15 min reading
- Review
- Last reviewed 2026-09-03
- Standard
- Accuracy standard
- Errata
Abstract
How viruses replicate inside a host cell.
What are the lytic and lysogenic cycles?
Short answer
The lytic and lysogenic cycles are two ways a virus replicates inside a host cell. In the lytic cycle the virus immediately hijacks the cell to make new viruses, then bursts (lyses) it to release them. In the lysogenic cycle the viral genome integrates into the host’s DNA and is copied silently for generations before switching to the lytic cycle later.
Concept preview
What you will be able to do
- 01Describe the five stages of the lytic cycle in order.
- 02Describe the lysogenic cycle and the role of the prophage.
- 03Compare the lytic and lysogenic cycles and explain when each is used.
- 04Explain how a lysogenic virus can 'hide' and later switch to the lytic cycle.
A virus has a single objective: to make more of itself. But there are two very different routes to that goal, and many viruses can use both. The lytic cycle is the smash-and-grab option — the virus takes over a cell immediately, mass-produces copies of itself, and bursts the cell open to release them. The lysogenic cycle is the long game — the virus slips its genome quietly into the host's own DNA and hides there, sometimes for generations, before switching to the lytic cycle later. Understanding both is the key to understanding everything from cold sores to HIV.
School Plan
The lytic & lysogenic cycles
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Related topics
Frequently asked questions
- What happens to the host cell in the lytic cycle?
- It is forced to make new virus particles and then bursts open (lyses), releasing them to infect other cells.
- How is the lysogenic cycle different?
- The viral DNA integrates into the host genome and is copied along with it, staying dormant until it enters the lytic cycle.