Algonquin College Health Program Assessment (AC-HPAT) Practice Exam

Which of the following best describes the relationship between a virus and its host cell during the lysogenic cycle?

1. The virus actively destroys the host cell

2. The virus integrates its genetic material into the host cell

3. The virus remains completely inactive

4. The virus rapidly replicates and exits the host

The correct answer is: The virus integrates its genetic material into the host cell

The correct choice highlights the nature of the lysogenic cycle, which is characterized by the integration of the virus's genetic material into the host cell's genome. During this phase, the viral DNA, referred to as a prophage when integrated, becomes a permanent part of the host's DNA. This integration allows the virus to replicate passively along with the host cell during cellular division, meaning that anytime the host cell replicates, it also replicates the viral genetic material without causing immediate harm to the host. This is distinctly different from the lytic cycle, where a virus would actively destroy the host cell to release new viral particles. In the lysogenic cycle, the virus usually remains dormant, and the host cell can continue its normal functions until certain triggers prompt the viral genetic material to exit the host genome and initiate the lytic cycle, leading to active reproduction of the virus and eventual cell lysis. The lytic cycle contrasts the lysogenic cycle by emphasizing active replication and destruction, which is why it’s important to differentiate between these two mechanisms of viral propagation. By understanding this nuanced relationship, one can appreciate how some viruses can persist in an organism without immediately causing disease, exemplifying the subtleties of viral behavior and host interactions.