While blizzards often feature extreme cold and heavy snow, there are actually no temperature or snow depth requirements for a storm to qualify as a blizzard. Occasionally, blizzard conditions will present when there is no precipitation.
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.efinition. 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.
The influenza virus can mutate so that the immune system cannot recognize the new virus and fight it off. This means that a person of any age can be reinfected time and time again.