Mutations Occur when there is an error in DNA replication Def: Change in genetic material Mutagens Physical or chemical agents that cause mutations Ex: high energy radiation (x-ray or UV) Ex. Chemicals (that are similar to DNA but cause incorrect base pairing)
Mutation Any change in the nucleotide sequence of DNA Large or small 2 Main types Base Substitutions (point mutations) Insertions or deletions
Point MutationA point mutation is a simple change in one base of the gene sequence. This is equivalent to changing one letter in a sentence, such as this example, where we change the 'c' in cat to an 'h': Original: The fat cat ate the wee rat. Point Mutation: The fat hat ate the wee rat.
Translocation: when one chromosome breaks off and attaches to another
Mutations NOT always harmful Some alter a protein in a beneficial way that may help species in a specific environment If mutation is present in organisms gametes, it may be passed off to off-spring Mutations are the ULTIMATE source for GENETIC DIVERSITY!!!