Reovirus particles. Coloured transmission electron micrograph (TEM) of particles (pink) of a reovirus infecting a dividing host cell. Nuclear chromatin is red. Viruses consist of a core of genetic material enveloped in protein coats. They rely on cellular genetic replication processes to make copies of themselves. A virus particle will infect a cell and then use the cell to make hundreds of copies of itself. This will kill the cell, and the next generation of virus particles is released to infect more cells. The reoviruses can cause febrile convulsions due to high temperatures when they infect humans. Reoviruses can also affect the gastrointestinal system (such as Rotavirus) and respiratory tract. Magnification: x2000 at 10 cm wide