Now that we know about both prokaryotic and eukaryotic cells, let's look at the endosymbiosis theory. This theory suggests that mitochondria and plastids in eukaryotic cells were once independent prokaryotic cells.
Avian influenza (AI) is an infectious viral disease of birds (especially wild water fowl such as ducks and geese), often causing no apparent signs of illness. AI viruses can sometimes spread to domestic poultry and cause large-scale outbreaks of serious disease.
1 Bird flu (avian flu or avian influenza) refers to strains of influenza that primarily affect wild and domesticated birds. 2  Bird flu is named H or N depending on the proteins found on the surface of the virus. 3  Bird flu symptoms include. 4  fever, 5  cough, 6  sore throat, 7  nausea.