1. The Flu virus enters the body through the respiratory system.
2. The virus will land on a cell in the respiratory system (nose, throat or lung).
3. Once on the cell the virus is absorbed inside and bursts to release it own RNA.
4. The virus RNA is taken to the nucleus.
5. The machinary inside the cells nucleus then starts to copy the virus RNA.
6. A million copied RNA leave the cell as new virus' killing the cell.