1. A permanent change in a cell’s DNA. MUTATION

2. Cells have checkpoints to repair damage missed earlier in DNA replication. Sometimes the cell doesn’t repair the damage. If the damage goes unrepaired it can result in mutation.

3. Radiation (X rays) UV light Mutagens A mutagen is a substance, such as a chemical, that causes mutations CAUSES OF MUTATIONS

4. MAIN CATEGORIES OF MUTATIONS Substitution: Involves a chemical change in one base pair. Missense Nonsense Frameshift: The addition or loss of a nucleotide that results in a change of the “frame” of the amino acid sequence Insertion Deletion Duplication: The copying of a nucleotide or amino acid sequence

5. A single base is changed to cause substitution of an amino acid. DNA = TAC GAG AGC CCA ATT RNA = AUG CUC UCG GGU UAA A.A. = Start leucine serine glycine stop DNA = TAC GAG CGC CCA ATT RNA = AUG CUC GCG GGU UAA A.A. = Start leucine alanine glycine stop MISSENSE MUTATION

6. Characterized by the improper development of the cartilage in legs and bones resulting in dwarfism ACHONDROPLASIA

7. A point mutation that results in a premature stop codon. DNA = TAC GAG AGC CCA ATT RNA = AUG CUC UCG GGU UAA A.A. = Start leucine serine glycine stop DNA = TAC GAG ATC CCA ATT RNA = AUG CUC UAG GGU UAA A.A. = Start leucine stop NONSENSE MUTATION

8. Characterized by the progressive weakening of many muscles in the body MUSCULAR DYSTROPHY

9. A mutation in which bases are added to the DNA sequence DNA = TAC GAG AGC CCA ATT RNA = AUG CUC UCG GGU UAA A.A. = Start leucine serine glycine stop DNA = TAC TGA GAG CCC AAT RNA = AUG ACU CUC GGG UUA A.A. = Start threonine leucine glycine leucine INSERTION MUTATIONS

10. Characterized by chronic inflammation of the intestinal tract causing diarrhea, abdominal pain, nausea, fever CROHNS DISEASE

11. A mutation in which part of the DNA is missing. DNA = TAC GAG AGC CCA ATT RNA = AUG CUC UCG GGU UAA A.A. = Start leucine serine glycine stop DNA = TAC AGA GCC CAA TTT RNA = AUG UCU CGG GUU AAA A.A. = Start serine arginine valine lysine DELETION MUTATIONS

12. Characterized by a high pitched cry, similar to a cat, during infancy Symptoms are lowered intellectual disability, delayed development, small head and weak muscle tone CRI DU CHAT

13. A type of mutation in which a portion of a genetic material or a chromosome is duplicated or replicated, resulting in multiple copies of that region. DNA = TAC GAG AGC ATT RNA = AUG CUC UCG UAA A.A. = Start leucine serine stop DNA = TAC GAG GAG AGC ATT RNA = AUG CUC CUC UCG UAA A.A. = Start leucine leucine serine stop DUPLICATION

14. Characterized by damage to nerves leading to atrophy of muscles in hands and lower legs CHARCOT-MARIE TOOTH DISEASE

15. The movement of a gene fragment from one chromosomal location to another, which can alter or abolish expression GENE TRANSLOCATION

16. Mutation is passed on to offspring and will be present in every cell of the offspring Alters mutated cell and future daughter cells May cause no result in a cell if the particular sequence is not needed. Cell death may occur May lead to cancer SOMATIC VS. GERM CELL MUTATION Somatic Germ

17. It’s estimated that mutations occur at the rate of 1 in every 50 million nucleotides. This means that each new cell contains some 120 new mutations. Should we be worried? NO – As much as 97% of our DNA does not encode anything. “junk DNA”

18. Can mutations be beneficial to us? Evolution – The changes seen in the inherited traits of a population from one generation to the next. MUTATION…GOOD?