Mutations. Definition. A Mutation occurs when a DNA gene is damaged or changed in such a way as to alter the genetic message carried by that gene. A Mutagen is an agent of substance that can bring about a permanent alteration to the physical composition of a DNA gene such that the genetic message is changed.
Since we can't see your choices we can only do so much to help you unfortunately. However, the word abiotic means non living. So if it's saying which is NOT an example of an abiotic factor, then your answer would be the choice that has to do with living. For example, plants, animals, etc.
Answer: Equestrian: An Olympic sport in which competitors ride horses, male and female riders compete head top head against each other in eventing, dressage and show jumping disciplines.
