Oncogens are genes which are involved in the
regulation of cell growth. If these genes are defect or do not express
correctly, it can lead to uncontrolled cell division and, in extreme
cases, to the formation of tumours. Opportunistic germs: Pathogens which cause illnesses
only in patients with weakened immune defences, such as is the case
with AIDS, are called opportunistic germs. Opsonization: The change in the surface of a pathogen or another
foreign body so that they can be ingested by pathogens is called opsonization.
Antibodies and the complement system opsonize extracellular bacteria,
preparing them for destruction by neutrophile cells and macrophages. |