Induced
Mutations
These are the mutations in which cause can be identified. More often they result from planned experiments, in which microbes are subjected to physical or chemical agents. The most common agents used for inducing mutations (mutagens) are, ultraviolet light, nitrous acid and several base analogs (the chemicals closely related to nitrogenous bases of DNA).
One base analog is 5-bromouracial. Other mutagens include, benzopyrene (in industrial soot and smoke), aflatoxin (a fungal toxin found in animal products and foods) etc.
