Viral Life Cycle Overview

Questions and Answers

What is the role of attachment proteins in the viral life cycle?

They help release new viral particles from the host.

They ensure the replication of viral genomes.

They bind the virus to specific host cells. (correct)

They inject nucleic acids into the host cell.

What initiates the lysogenic cycle in a virus?

The binding of the virus to the host cell.

The release of viral particles from the host cell.

The injection of the virus's nucleic acids into the host cell. (correct)

The injection of unique viral proteins into the host cell.

Which statement accurately describes the impact of viral infection on host cells?

Viruses enhance the cell's ability to produce proteins.

Viruses completely replace the host cell's DNA with their own.

Viruses integrate into the host cell's cellular processes for mutual benefit.

Viruses divert the host cell's energy to replicate their own genomes. (correct)

What happens to the host cell after it has produced a considerable number of viral particles?

It bursts, leading to the release of viral particles. Signup and view all the answers

Why do different viruses infect different types of cells?

Because of variations in attachment protein recognition. Signup and view all the answers

What key event occurs during the process of injection of unique viral proteins?

The host cell is forced to make viral proteins and replicate viral genomes. Signup and view all the answers

Which cycle describes the dormant phase when a virus's nucleic acids integrate into the host genome?

Lysogenic cycle Signup and view all the answers

Which characteristic is NOT true regarding viral genomes?

They are always circular in structure. Signup and view all the answers

Study Notes

Viral Life Cycle

Viruses replicate by infecting a host cell instead of undergoing cell division.
The success of viral reproduction is hinged on the ability to infect a host cell.

Virus Binding to Host Cells

Attachment proteins enable viruses to bind specifically to host cells.
Different viruses possess unique attachment proteins, determining the types of cells they can infect.
Example: HIV's attachment proteins bind to receptors on human T-cells.

Injection of Nucleic Acids

Following attachment, viruses inject their nucleic acids (DNA or RNA) into the host cell.
This stage is part of the lysogenic cycle, where the virus introduces its genetic material into the host.

Injection of Unique Viral Proteins

Some viruses can inject unique viral proteins into the host cell, aiding in hijacking the host's cellular machinery.
This manipulation redirects the host's energy from cellular functions to viral replication, severely harming the host cell.

Release from Host Cell

Viral particles accumulate and eventually burst from the host cell in a process known as lytic release.
Released viruses seek out new host cells to infect and continue their life cycle.

Host Cell Death

The original host cell dies from damage, particularly due to holes created in its cell membrane.
This stage is part of the lytic cycle, signifying the death of the host cell following viral replication.

Latency

Viruses can enter a latent state during the lysogenic cycle, becoming dormant and ceasing reproduction of viral particles.
Reactivation can occur due to various triggers, such as stress, leading the virus to resume production.
Reactivation allows the host to become ill without any new external viral infections, as the dormant virus becomes active again.

Description

Explore the critical processes involved in the viral life cycle, from the mechanisms of virus binding to host cells to the injection of nucleic acids. This quiz covers important concepts such as attachment proteins and the impact on host cellular functions. Test your knowledge of how viruses replicate within host organisms.