Emerging viruses
Likely the human activity that is most closely associated with the emergence of viruses in humans is urbanization. The closeness caused the viruses to promulgate more efficiently than in communities where there not as many people.
Viruses that are harmless to humans can be used to infect bacteria or other pests eg rabbits
Bacteria,fungi,or parasitic worms invade the human body.
it isn't
No. Any and all viruses are parasitic. There may not be any helpful viruses, but there are certainly a large quantity of harmless viruses, which doesn't infect humans, but rather specific animals or plants.
useful effect viruses
Viruses and some bacteria aren't useful.
Regardless of the pathogenicity of certain viruses, benign viruses CAN be used to carry vaccines into the blood stream and cells, thereby being useful. Other viruses, such as those which live in (or off of) certain plants cause that plant to produce certain useful (at least to humans) chemicals such as anti-bacterial compounds. Viruses will also most likely be the first carrier vector of DNA therapy for a variety of human and animal illnesses, since they easily enter cell membranes and can insert their DNA or RNA into the host cell's own genetic material
Emerging viruses
Its useful to see very small microorganisms & useful to study about small viruses etc.
the viruses help the immune system adapt and get stronger
the flu...
Snakes don't help humans..but they are useful for entertainment..but are dangerous.
Bacteria, fungi, and parasites are larger than viruses. They are all types of microorganisms that can cause infections in humans and other living organisms.
its not useful for the refrigerator its useful for humans only....
no it usually isn't and it can cause viruses to your computer