Virus

A microscopic infectious agent that can only replicate inside the living cells of organisms, often causing diseases in plants, animals, and humans.

 

Pathogen:

A biological agent, such as a virus, bacterium, or fungus, that causes disease or illness in its host.

 

Genome:

The complete set of genetic material (DNA or RNA) present in a virus, containing instructions for the virus’s structure, function, and replication.

 

Host Cell:

The living cell invaded and used by a virus for replication. The virus hijacks the host cell’s machinery to reproduce itself.

 

Capsid:

The protein coat that surrounds and protects the genetic material of a virus, providing structural integrity.

 

Envelope:

 A lipid bilayer that surrounds some viruses, derived from the host cell membrane during the viral exit process, contributing to the virus’s structure.

 

Retrovirus:

A type of RNA virus that can reverse transcribe its RNA into DNA, integrating the genetic material into the host cell’s genome. HIV is an example of a retrovirus.

 

Antigen:

A molecule, usually a protein or carbohydrate, on the surface of a virus that triggers an immune response in the host organism.

 

Immune Response:

The body’s defense mechanism against viruses and other pathogens, involving the activation of immune cells and the production of antibodies.

 

Antibody:

Proteins produced by the immune system in response to the presence of a virus, which can neutralize or tag the virus for destruction.