The answer is acquired gene mutation.
Gene mutation is of 2 types- hereditary mutation and acquired mutation.
Hereditary mutations are inherited by parents and lasts a lifetime and it is present in each and every cell in the body like sickle cell anemia, cystic fibrosis.
Acquired mutations does not pass onto the next generation and it happens due to ultraviolet radiation exposure or when a DNA copies itself during cell division like melanoma.
