What is the difference between bacteria, a virus and a pathogen?
What are Bacteria? Bacteria are microscopic organisms whose single cells have neither a membrane-bounded nucleus nor other membrane-bounded organelles like mitochondria and chloroplasts. Another group of microbes, the archaea, meet these criteria but are so different from the bacteria in other ways that they must have had a long, independent evolutionary history since close to the dawn of life. In fact, there is considerable evidence that you are more closely related to the archaea than they are to the bacteria! VIRUS Viruses are unusual, incredibly tiny particles that are either living or non-living organisms, depending on your definition of ‘life’. If they’re floating around in the air or sitting on a rock, they’re inert … not alive at all. They don’t do any of the normal things we associate with living organisms. But if they come into contact with a suitable living cell, they infect and take over the cell, and reproduce themselves. A virus is a tiny bundle of genetic material – ei
