Introduction to viruses Reference Libraries
A virus is a small infectious agent that replicates inside the living cells of organisms. It is a small infectious agent that can replicate only inside the living cells of organisms. Most are too small to be seen by anything but a microscope and they infect all organisms from animals to plants to bacteria. The first one discovered was the tobacco virus in 1898. Since then around 5,000 viruses...
- The navel or umbilicus.
- In Greek archaeology: A central boss, as on a shield, a bowl, etc.
- A sacred stone in the temple of Apollo at Delphi, believed by the Greeks to mark the 'navel' or exact center-point of the earth.