Answer: Mutation
Mutation is an alteration in the base-pair sequence of an individual's DNA; may arise spontaneously or following exposure to a mutagen.
Explanation:
A mutation could occur when a chemical agent known as mutagen changes the genetic material, usually DNA, of an organism and this increases the frequency of mutations above the natural background level.
Other causes of mutation include:
- spontaneous mutation
- error in DNA replication, repair and recombination
- induced mutations by mutagens exposure
Examples of mutagens are X-ray, heavy metals such as cadmium, lead etc
