Living things come in all shapes and sizes. But all living things seem to have one thing in common. They all contain cells.
Some organisms consist of only a single cell.
Other organisms, like you, are made up of many cells. Unlike these organisms, Viruses are not cells and do not contain cells. Viruses are actually tiny particles that contain hereditary material. Because viruses are not cells, they cannot perform the life functions of living cells . They cannot, for example, take food in food or get rid of wastes.