Mutation (noun)

1. A change or alteration, especially in DNA, that results in a new genetic characteristic.
2. A genetic variation that occurs naturally or as a result of exposure to radiation or chemical agents.
3. A change or modification in form, nature, or quality.

Origin:

From latin mutatio (a change), from mutare (to change).

Examples:

1. The mutation in the gene caused a rare form of cancer.
2. The mutation of the virus made it more contagious.
3. The mutation of the butterfly was caused by exposure to radiation.
4. The mutation in the plant gave it new and improved features.
5. The mutation in the bacteria made it resistant to antibiotics.