Viruses

Definition

Viruses are infectious agents that require a host cell to replicate and propagate their genetic material. They can infect all forms of life, including bacteria, plants, animals, and humans.

5 Must Know Facts For Your Next Test

1. Viruses contain either DNA or RNA as their genetic material, but not both.
2. They hijack the host's cellular machinery to replicate their genomes and produce viral proteins.
3. During infection, viruses can integrate their genetic material into the host genome, which can affect the host's DNA replication process.
4. Viruses do not have their own ribosomes and rely on the host cell's ribosomes for protein synthesis.
5. The replication cycle of viruses involves attachment, penetration, uncoating, replication, assembly, and release.

Review Questions

• What type of genetic material can be found in viruses?
• How do viruses replicate if they lack cellular machinery like ribosomes?
• Describe the basic steps involved in the viral replication cycle.

Related terms

Bacteriophage:

A virus that specifically infects bacteria.

Retrovirus: A type of virus that uses reverse transcriptase to convert its RNA into DNA after entering a host cell.

Lysogenic Cycle:

A viral replication cycle where the virus integrates its genome into the host cell's DNA and replicates along with it without causing immediate lysis.