Question

True or false: Most viral genes are not expressed during latent infection

Answer 1

The statement is 'true' because during latent infections, viruses remain dormant within host cells, leading to most viral genes not being actively expressed. This allows the viruses to preserve their genomes until favorable conditions return and they may reactivate.

Step-by-step explanation:

Latent Infection and Viral Gene Expression

The statement 'Most viral genes are not expressed during latent infection' is true. During latent infections, viruses like herpes simplex, which can cause herpes in humans, remain dormant within host cells. In this state, the viral genome may exist as circular molecules outside of the host's chromosome or may integrate into the host genome as proviruses, leading to a period of dormancy where most viral genes are not being actively expressed.

Consequently, no viral particles are produced, and the viruses do not cause symptoms. This dormancy allows the viruses to preserve their genome during unfavorable conditions. They may reactivate, however, under certain triggers, leaving the latent state to enter the lytic cycle, producing new virions and potential disease symptoms.

Answer 2

The statement that most viral genes are not expressed during latent infection is true. In this state, viruses remain dormant within the host cell and express minimal to no viral genes, only emerging from latency when triggered by certain conditions to replicate and cause symptoms.

Step-by-step explanation:

True or false: Most viral genes are not expressed during latent infection. The statement is true. During a latent infection, viruses enter a dormant phase where most of their genes are not expressed. Viruses capable of causing latent infections can initially trigger an acute infection, becoming dormant afterward. Latent viruses remain hidden within the host cell, existing either as circular viral genome molecules outside of the host chromosome or integrated into the host genome as proviruses. During this dormancy, these viruses do not usually cause symptoms and can be difficult to detect without specific viral diagnostic tests.

For viruses like the herpes simplex virus, which causes herpes in humans, the latency period means that the virus exists in nervous tissue for long periods, limiting the production of new virions. Later, the virus can leave this latent phase, usually when triggered by certain stimuli, resulting in replication and symptom manifestation.

In summary, while the host cell experiences unfavorable conditions, viruses enter a state called latency, during which their genomes are preserved without significant expression of viral genes. This adaptation can allow the virus to survive for extended periods before re-activating during the lytic cycle once conditions become favorable again.