Different Types of Viruses – Biology Poster, 36×26
by American Educational Products

A virus is a small infectious agent that is only capable of replicating itself when inside the living cells of another organism. They can be found in almost every ecosystem on the planet, and are considered to be one of the most abundant types of biological entities. They are capable of infecting all types of life forms, from animals and plants to microorganisms, bacteria and archaea.

Because they do carry their own genetic material and are capable of reproduction and evolution through natural selection, some scientists consider viruses to be life forms, because of their lack of key characteristics like cell structure, they are generally not considered as such by the scientific community as a whole. Capable of spreading in many was, they are often transmitted from plant to plant by way of insects that feed on plant sap, while in animals, they tend to be carried by blood-sucking insects. A key factor in the spread of a virus is its “host rage”: the broader this range is, the more species it is capable of infecting.

The microscope slide images in this poster explore eight viruses that are capable of affecting humans, animals, and plants. Each one gives a brief explanation of the image, and what it does to its host.