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Gene Mutation

Gene Mutation . Mutation. Mutation: change in DNA sequence Causes of mutation:. Spontaneous Mutation. Spontaneous mutation in gene for a blood clotting factor, leading to hemophilia. . Point Mutations. Point mutation: change in one or a few DNA nucleotides. Substitutions .

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Gene Mutation

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  1. Gene Mutation

  2. Mutation Mutation: change in DNA sequence Causes of mutation:

  3. Spontaneous Mutation

  4. Spontaneous mutation in gene for a blood clotting factor, leading to hemophilia.

  5. Point Mutations Point mutation: change in one or a few DNA nucleotides

  6. Substitutions

  7. Examples of Substitutions

  8. Effects of Substitutions on the Protein Sequence

  9. Applying Your Knowledge HbA • The mutation that leads to Sickle-cell Disease (HbS) is a • Silent Mutation • Synonymous mutation • Missense Mutation • Nonsense Mutation • None of these HbS

  10. Applying Your Knowledge • The mutation that leads to the insertion of valine into HbS is due to a • Transition • Transversion • Both a transition and a transversion • Neither a transition nor a transversion HbS

  11. Frameshift Mutations Frameshift mutation: deletion or insertion of nucleotide bases, not in multiples of three Causes a change in the “reading frame” of codons for the protein sequence

  12. Insertions in multiples of three nucleotides restore the reading frame.

  13. Tandem Duplications Tandem duplications: adjacent or nearby repeat of part of a gene’s sequence

  14. Expanding Triplet Repeats Expanding Triplet Repeats: increase in number of a specific trinucleotide within a gene from generation to generation

  15. Expansion of the Trinucleotide Repeat for Huntington’s Disease Linda (6,22) Allen (46,13) age 50 Jama (7,18) Andrew (69,6) age 37 Kristen (64,22) age 40 Ann (64,22) age 39 Bill (8,12) Greg (11,19) Debbie (13,6) Christina (93,7) age 26 Joseph (7,6) Nathaniel (72,19) age 35 Paula (13,12) Evan (not tested)

  16. An insertion of one or two nucleotide bases causes a _____ . Replacing one nucleotide with another causes a ____. A repeat of part of a gene’s sequence in a nearby region is a ______. Substitution Frameshift Mutation Tandem Duplication Expanding Triplet Repeat Applying Your Knowledge

  17. Repair of DNA

  18. Repairing UV-Damaged DNA Use of enzymes to remove and replace region with thymine-thymine dimer Use of light and enzymes to reverse thymine-thymine dimers

  19. Photoreactivation

  20. Mismatch Repair: Correcting Errors in DNA Replication

  21. Xeroderma Pigmentosum: Accumulation of DNA Damage Leads to Skin Cancer

  22. Method of replacing a DNA region that was damaged by radiation or chemicals Method that uses white light to repair thymine-thymine dimers produced by ultraviolet radiation Method of replacing DNA region where a nucleotide was incorrectly placed during replication Mismatch Repair Excision Repair Photoreactivation Applying Your Knowledge

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