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.
vian influenza (AI)--the bird flu--is a virus. that infects wild birds (such as ducks, gulls, and. shorebirds) and domestic poultry (such as chick-. ens, turkeys, ducks, and geese). There is a flu for. birds just as there is for humans and, as with people, some forms of the flu are worse than others. AI viruses are classified by a combination of two. groups of proteins: the hemagglutinin or H proteins, of. which there are 16 (H1-H16), and neuraminidase or N. proteins, of which there are 9 (N1-N9).