Virus are micro organisms. They can be deadly and harmful, but also helpful sometimes. 

Virus:

There are three types of viruses.

1. Bacteriophage [Virust that attacks bacteria]

   

 2. Influenza [Virus that attacks human cells]

 

 

3. Virus that attacks plant cells.

Size: They are the smallest organisms in this world. They can only be seen under an electon microscope. 

They are considered as living and nonliving.

Why are they considered as living? It is because they have the protien coat and the DNA/RNA thread in them.

Why are they considered as Non Living? It is because they cannot survive on their own, they depend on a host cell.

They are parasites. Which means they are harmful.

They can change their shapes, so it becomes difficult for the immune sysstem to fight them, although they are able to kill the virus somehow.

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Written by Haider Khan

Student of Olevels