Definition:
In biology, a sudden change in a gene or unit of hereditary material that results in a new inheritable characteristic. In higher animals and many higher plants, a mutation may be transmitted to future generations only if it occurs in germ -- or sex cell -- tissue; body cell mutations cannot be inherited. Changes within the chemical structure of single genes may be induced by exposure to radiation, temperature extremes, and certain chemicals. The term mutation may also be used to include losses or rearrangements of segments of chromosomes, the long strands of genes. Mutation, which can establish new traits in a population, is important in evolution. As related to HIV: During the course of HIV disease, HIV strains may emerge in an infected individual that differ widely in their ability to infect and kill different cell types, as well as in their rate of replication. Of course, HIV does not mutate into another type of virus.
In biology, a sudden change in a gene or unit of hereditary material that results in a new inheritable characteristic. In higher animals and many higher plants, a mutation may be transmitted to future generations only if it occurs in germ -- or sex cell -- tissue; body cell mutations cannot be inherited. Changes within the chemical structure of single genes may be induced by exposure to radiation, temperature extremes, and certain chemicals. The term mutation may also be used to include losses or rearrangements of segments of chromosomes, the long strands of genes. Mutation, which can establish new traits in a population, is important in evolution. As related to HIV: During the course of HIV disease, HIV strains may emerge in an infected individual that differ widely in their ability to infect and kill different cell types, as well as in their rate of replication. Of course, HIV does not mutate into another type of virus.

