A permanent alteration in the DNA sequence.
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. A gene mutation is a permanent alteration in the DNA sequence that makes up a gene, such that the sequence differs from what is found in most people. Mutations range in size; they can affect anywhere from a single DNA building block (base pair) to a large segment of a chromosome that includes multiple genes. 1 For example, the disorder sickle cell anaemia is caused by a mutation in the gene that instructs the building of a protein called haemoglobin. 2  This causes the red blood cells to become an abnormal, rigid, sickle shape. 3  However, in African populations, having this mutation also protects against malaria. What is a mutation? A mutation is a change that occurs in our DNA sequence, either due to mistakes when the DNA is copied or as the result of environmental factors such as UV light and cigarette smoke. A chromosome mutation is an unpredictable change that occurs in a chromosome. These changes are most often brought on by problems that occur during meiosis (cell division process of gametes) or by mutagens (chemicals, radiation, etc.). Missense. A change in DNA sequence that changes the codon to a different amino acid. Not all missense mutations are deleterious, some changes can have no effect. Because of the ambiguity of missense mutations, it is often difficult to interpret the consequences of these mutations in causing disease. Mutation. Definition. noun, plural: mutations. (general). A change in or the process of changing, e.g. nature, form or quality. (genetics). (1) A permanent, heritable change in the nucleotide sequence in a gene or a chromosome; the process in which such a change occurs in a gene or in a chromosome. Point mutations are single base changes, that do not affect the reading frame; that is, the mutation only makes a single change in a single codon, and everything else is undisturbed. There are three types of point mutation:
http://www.brooklyn.cuny.edu/bc/ahp/BioInfo/MUT/Mut.Definition.html http://ghr.nlm.nih.gov/handbook/mutationsanddisorders/genemutation http://www.yourgenome.org/facts/what-is-a-mutation http://www.yourgenome.org/facts/what-is-a-mutation http://biology.about.com/od/genetics/ss/chromosome-mutation.htm http://www.uvm.edu/~cgep/Education/Mutations.html http://www.biology-online.org/dictionary/Mutation http://utminers.utep.edu/rwebb/html/what_is_a_mutation_.html
Quizlet define gene mutation