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MUTATION. “Mutation : it is the key to our evolution. It has enabled us to evolve from a single-celled organism into the dominant species on the planet. This process is slow, and normally taking thousands and thousands of years. But every few hundred millennia, evolution leaps forward .”
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“Mutation: it is the key to our evolution. It has enabled us to evolve from a single-celled organism into the dominant species on the planet. This process is slow, and normally taking thousands and thousands of years. But every few hundred millennia, evolution leaps forward.” - Professor Charles Xavier
OVERVIEW • Gene Mutation: a change in the specific order of the A, G, C, and T bases in a particular gene • “Spirit” Bears (Kermode Bears) • White due to a mutation in the gene for fur colour • Affects 1 of 10 black kermodebears
THE EFFECTS OF MUTATIONS • 3 types of mutations: • Deletion (one base is missing) • Addition (one base is added) • Substitution (one base is substituted with another • Mutations can be positive (beneficial), negative (harmful), or neutral
POSITIVE MUTATION • A mutation that benefits an individual EXAMPLE: HIV is a virus that results in AIDS. • Some people have a mutated gene that codes for proteins that prevent HIV infection EXAMPLE: Plants that have developed resistance to bacteria/fungi
NEGATIVE MUTATION • Small changes in DNA base sequences that cause harm to the individual • Reduces the likelihood of reproduction or survival EXAMPLE: Sickle Cell Anemia • Substitution of base A for base T in 1 place results in misshapen hemoglobin (red blood cells)
Result: • can’t carry oxygen • blocks blood flow, causing pain and organ damage
EXAMPLE: Cystic Fibrosis • can be caused by 1300+ mutations in 1 gene • Protein is incorrectly made, causing a mucus buildup • Chloride levels build, resulting in respiratory problems
NEUTRAL MUTATION • The substitution of 1 base for another that does not affect the individual • Same protein will be made without error EXAMPLE: The Spirit Bear • The mutated fur colour does not impact the bear
MUTAGENS • Substances or factors that can cause mutations in DNA • Viruses can cause DNA to be misread or copied incorrectly • When DNA is damaged the proteins will not be made correctly • Cigarette smoke, x ray radiation, UV rays, pollutants (mercury), and household chemicals