Answer: Mutation
Explanation: Mutation is a change in DNA sequence, it may occur due to error when the DNA is copied or it can arise from various environmental factors such as exposure to chemicals, UV radiation, Highly infectious microbes.
Mutation maybe spontaneous. Acquired mutations occur at some point in a person's life and are present only in certain cells, not in every cell in the body while some may target a tissue, an organ or an entire system.
