Most viruses are only 20–400 nanometers in diameter, whereas human egg cells, for example, are about 120 micrometers in diameter, and the E. Not only are viruses microscopic, they are smaller than many other microbes, such as bacteria. A virus that is outside of a host cell is known as a virion. As such, there is some debate as to whether or not viruses should be considered living organisms. They may use an animal, plant, or bacteria host to survive and reproduce. Viruses are tiny infectious agents that rely on living cells to multiply.
