Answer:
Mutation
Explanation:
The mutation is a change in a gene. This always put an adverse impact on the individual. A mutation may be heritable and non-heritable. The mutation leads to variation and natural selection which results in evolution. The sickle cell anaemia, the sudden growth of excess hair in the face of the male are the examples of mutation. The mutation is fatal as it happens in DNA and the defective nucleotide synthesise repeatedly and it is difficult to control.
