Definition of Mutagen
Mutagen is an agent that might be physical, chemical or even biological that has a tendency to cause changes in the genetic material of an organism. This alteration in the DNA becomes a reason for a number of genetic abnormalities. The mutations can be caused in somatic cells as well as germ cells. Somatic mutations remain in the body and cause cancer. On the other hand, germline mutations are passed to the next generation and give rise to birth defects.
The mutagens cause changes in the structure of the chromosome by deleting, duplicating, inserting, translocating certain bases. They can also dysregulate processes such as translation and transcription. Organisms have a DNA repair mechanism through which most of the time these mutations do not cause any abnormality and the genetic material restore its original form.