Viruses are prolific. They have been found in almost all parts of the Earth, including the Arctic. They infect nearly every form of life from the simplest unicellular organism (bacteria) to complex mammals, such as humans.

The structures of all human viruses have several common attributes. First is their incredibly small scale. There are 10 x10+9 nanometers in a meter. Viruses are so minuscule that they can only be visualized using electron microscopes. Another common structural property of viruses is that they are constructed from protein subunits. Subunits are simply identical proteins. The virus is therefore constructed

Some common words found in the essay are:
DNA RNA, Theory Viruses, Ebola Marburg, host cell, , viral genome, property viruses, viral genome stays, whereas host cell, arises directly pre-existing, components virus, arises directly, host possesses, genome stays, nucleic acid, hepatitis hepatitis, directly pre-existing,
Approximate Word count = 469
Approximate Pages = 2 (250 words per page double spaced)