Biology-21.1 Viruses

Front

What is a virus?

Back

A virus is a microscopic infectious agent that can only replicate inside the living cells of an organism.

Front

How does a virus reproduce?

Back

A virus reproduces by invading a host cell and using the host's cellular machinery to make copies of itself.

Front

What is the common cold caused by?

Back

The common cold is caused by viruses, primarily rhinoviruses.

Front

What is a bacteriophage?

Back

A bacteriophage is a type of virus that specifically infects and kills bacteria.

Front

What is the difference between lytic and lysogenic infections?

Back

In lytic infections, the virus immediately replicates and destroys the host cell. In lysogenic infections, the viral DNA integrates into the host DNA and can remain dormant.

Front

What is the tobacco mosaic virus?

Back

The tobacco mosaic virus is a well-known plant virus that infects tobacco and other plants, causing mottled leaves.

Front

What is the role of viral DNA in a lysogenic infection?

Back

During a lysogenic infection, the viral DNA is inserted into the host DNA and can remain inactive for a period.

Front

Can viruses be treated with antibiotics?

Back

No, antibiotics are ineffective against viruses; they only work against bacterial infections.

Front

What is an example of a disease caused by a virus?

Back

Influenza (the flu) is an example of a disease caused by a virus.

Front

What is the structure of a virus?

Back

A virus typically consists of genetic material (DNA or RNA) surrounded by a protein coat called a capsid.