A permanent alteration in the DNA sequence that makes up a gene, such that the sequence differs from what is found in most people. A permanent alteration in the DNA sequence that makes up a gene.
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. (2) A mutant, or an individual exhibiting such a change. Definition of GENE MUTATION. : mutation due to fundamental intramolecular reorganization of a gene — compare point mutation. See gene mutation defined for kids. ADVERTISEMENT.  In biology, a mutation is a permanent change of the nucleotide sequence of the genome of an organism, virus, or extrachromosomal DNA or other genetic elements. Mutations result from damage to DNA which is not repaired, errors in the process of replication, or from the insertion or deletion of segments of DNA by mobile genetic elements. Mutations may or may not produce discernible changes in the observable characteristics (phenotype) of an organism. 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. Once the gene has been damaged or changed the mRNA transcribed from that gene will now carry an altered message. Radiation can also cause double strand breaks in the DNA molecule, which the cell's repair mechanisms cannot put right. Sunlight contains ultraviolet radiation (the component that causes a suntan) which, when absorbed by the DNA causes a cross link to form between certain adjacent bases. Mutations. Mutation is a change in DNA, the hereditary material of life. An organism's DNA affects how it looks, how it behaves, and its physiology  all aspects of its life. So a change in an organism's DNA can cause changes in all aspects of its life. Mutations are random 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.  Medical Definition of MUTATION. 1. : a relatively permanent change in hereditary material involving either a physical change in chromosome relations or a biochemical change in the codons that make up genes; also: the process of producing a mutation. 2. : an individual, strain, or trait resulting from mutation. 3. a: a relatively permanent change in hereditary material involving either a physical change in chromosome relations or a biochemical change in the codons that make up genes; also: the process of producing a mutation b: an individual, strain, or trait resulting from mutation. point mutation a mutation resulting from a change in a single base pair in the DNA molecule. somatic mutation a genetic mutation occurring in a somatic cell, providing the basis for mosaicism. suppressor mutation the correction of the effect of a mutation at one locus by a mutation at another locus.  genetic mutation - (genetics) any event that changes genetic structure; any alteration in the inherited nucleic acid sequence of the genotype of an organism. 
http://www.biology-online.org/dictionary/Mutation http://www.merriam-webster.com/dictionary/gene%20mutation https://en.wikipedia.org/wiki/Gene_mutation http://www.brooklyn.cuny.edu/bc/ahp/BioInfo/MUT/Mut.Definition.html http://evolution.berkeley.edu/evolibrary/article/evo_18 http://ghr.nlm.nih.gov/handbook/mutationsanddisorders/genemutation http://www.merriam-webster.com/dictionary/mutation http://medical-dictionary.thefreedictionary.com/genetic+mutation http://www.thefreedictionary.com/genetic+mutation
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