1 / 33

Understanding Mutations: Impacts on Genetic Information Flow

Explore the central dogma of molecular biology and learn about mutations, their types, causes, and effects. Discover how mutations affect genetic information flow from DNA to RNA to proteins. Understand the significance of mutations in shaping an organism's characteristics and genetic diversity.

dhernandez
Download Presentation

Understanding Mutations: Impacts on Genetic Information Flow

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Central Dogma of Molecular Biology • Genetic information flows in one direction – • from DNA to RNA to proteins.

  2. Bellringer What do these words mean to you?Write a short 2 word definition for each • 1. Mutation • 2. Duplication • 3. Deletion • 4. Insertion • 5. Translocation • 6. Inversion • 7. Substitution

  3. KEY CONCEPT Mutations are changes in DNA that can affect phenotype

  4. What are Mutations? (video link)

  5. Mutations are changes to DNA that may be • Harmful • Helpful • Have no effect.

  6. When Mutations Occur • Errors can occur during: DNA Replication Protein Synthesis Meiosis .

  7. Causes of Mutations 2. Mutagens – Environmental factors that cause changes in DNA Examples: - Radiation - Chemicals in environment .

  8. The effect mutations have on an organism’s physical characteristics depends on: • The number and type of genes involved • Type of cell the mutation occurs in – somatic or sex

  9. Mutations in Somatic Cells: • Affect only the organism they occur in. • Cannot be passed to offspring.

  10. Mutations in Sex (Germ) cells: • May be passed to offspring

  11. Two Categories of Mutations: 1.Single Gene– affects one gene – usually caused by an error in DNA replication 2. Chromosomal – affects chromosomes – usually error in meiosis . Usually more harmful since many genes are affected.

  12. Types of Chromosomal Mutations • Translocation • Duplication • Nondisjunction • Deletion • Inversion

  13. TRANSLOCATION(“transfer location”) • Piece of one chromosome breaks off and moves to a nonhomologouschromosomes.

  14. DUPLICATION. • Two or more copies of the same gene on a chromosome .

  15. NONDISJUNCTION • Homologous chromosomes don’t separate in Anaphase I • Sister chromatids don’t separate in Anaphase II

  16. Deletion • Section of chromosome containing one or more genes is removed

  17. Inversion • Section of a chromosome flips its position

  18. Single Gene Mutations • Usually occur in DNA replication • Affect one gene and the protein made from it

  19. Frameshift Mutation • Caused by adding or removing 1-2 bases • Changes the reading frame • .

  20. Type of Frameshift Mutation .Deletion - one or more bases are deleted; shifts the reading frame

  21. Type of Frameshift Mutation Insertion - one or more bases are added; shifts the reading frame

  22. mutated base Point Mutations • One nucleotide is replaced by another.

  23. Types of Point MutationsDetermined by their outcomes

  24. Nonsense point mutation • Change codes for a STOP codon • Full protein not made • “NO” STOP

  25. Missense Point Mutation * Codes for wrong amino acid* May be harmful or beneficial – depends…

  26. Silent point mutationDoes not result in a different amino acid or protein made.DNA changes but its expression (phenotype) does not.

  27. Results of mutations may be: • Harmful – needed protein isn’t made • Have NO EFFECT – are not harmful or helpful • Beneficial are favored by natural selection – rarely occurs

  28. Mutations increase genetic variety Natural selection favors mutations that provide survival advantage.

  29. Laron Syndromemutation that causes dwarfism also protects against cancer and diabetes. • ABC Evening News - Laron Syndrome

  30. Mutations in body cells do not affect offspring. • Only Mutations in sex cells affect offspring. • Natural selection favors mutations that provide an adaptation that has survival advantage

More Related