What is a Virus

A virus is a very small organism that infects hosts,  The most important thing to understand about these are that they can not produce their own energy and metabolism, so they need to live inside another life forms cells.

Viruses are everywhere and are the most abundant type of biological entity..

Virions (Virus Particles) have two or  three components

1) Genes to replicate which is either DNA or RNA

2) A protein that coats and protects the genetic material.

3) Sometimes they have a lipid shell that further protects the protienacious coat, usually present when the virus is not inside the cell.

Bacteria are usually 100 times bigger than viruses.  viruses infect and attack bacteria all the time. 

Viruses are between 20 and 300 nonometers.  You can no0t see them with your eyes.

Our immune systems usually do a good job defending our bodies form viral attacks,  After a virus attack, the body remembers the virus and build an immunity to further attacks.

Some viruses our bodies can not defend against.  In addition, viruses mutate so quickly that its defense against one specific form of a virus may not be effective against its new mutated form.

Antibiotics have no effect on viruses.

Antiviral drugs are available for some viruses.




picture of virus replication