1. Cell Differentiation  http://www.youtube.com/watch?v=cyaVEotYsY0

2. Cell Specialization & Gene Expression  We have 100 trillion cells, but they don’t all look the same (200 types): Neuron Cell Epithelial (Skin) Cells Red Blood Cells Muscle CellSperm Cell

3. Cell Specialization & Gene Expression  All of these cells contain the same exact copy of DNA (except sperm and egg), BUT: Image Source: questgarden.com Same DNA, but only some genes are expressed Definitions **Gene: a portion of DNA that codes for a protein **Gene Expression: the proteins formed by the decoding of specific genes in a cell

4. Exhibition Step 1  Pick a cell  Answer questions on planning sheet  Use as introduction to your hero and story

5. 10 Human Mutations  http://io9.com/10-unusual-genetic-mutations-in-humans- 470843733 http://io9.com/10-unusual-genetic-mutations-in-humans- 470843733

6. Mutations  Mutation: A change in a DNA sequence. May or may not affect gene expression (the protein).

7.  Mutagen: something that causes a mutation

8. MutationsPointSilentNot SilentFrameshiftInsertionDeletion Mutations & Gene Expression

9. Image Source: waynesword.palomar.edu Recall: 64 codons, only 20 amino acids.

10. Mutations  Point Mutation: Change in one nucleotide 1. T H E / F A T / C A T / A T E / T H E / R A T T H E / F A T / K A T / A T E / T H E / R A T 2. T H E / F A T / C A T / A T E / T H E / R A T T H E / F A T / B A T / A T E / T H E / R A T “Silent Mutation” Not Silent Message still sounds the same Message sounds different

11. Mutations & Gene Expression  Point Mutations (cont.)  Normal:  Point (Silent):  Point (not silent): DNA Template Strand TACGTGCGAACCTGAATT mRNA Strand AUGCACGCUUGGACUUAA Protein MethionineHistidineAlanineTryptophanThreonineSTOP DNA Template Strand TACGTGCGCACCTGAATT mRNA Strand AUGCACGCGUGGACUUAA Protein MethionineHistidineAlanineTryptophanThreonineSTOP Recall: 64 codons, only 20 amino acids; helps prevent protein changes! DNA Template Strand TACGTGCGAACGTGAATT mRNA Strand AUGCACGCUUGCACUUAA Protein MethionineHistidineAlanineCysteineThreonineSTOP Just one amino acid change can change an entire protein!

12.  Sickle Cell Anemia

13. Mutations & Gene Expression  Frameshift Mutations: insertion or deletion of nucleotide(s) results in the reading of codons to shift. 1. T H E / F A T / C A T / A T E / T H E / R A T T H E / F A E / T C A / T A T / E T H / E R A / T 2. T H E / F A T / C A T / A T E / T H E / R A T T H E / A T C / A T A / T E T / H E R / A T Insertion Letters after insertion are shifted to the right All Nonsense = Message Destroyed Deletion All Nonsense = Message Destroyed Letters after insertion are shifted to the left

14. Mutations & Gene Expression  Frameshift Mutations (cont.)  Normal:  Frameshift Insertion:  Frameshift Deletion: DNA Template Strand TACGTGCGAACCTGAATT mRNA Strand AUGCACGCUUGGACUUAA Protein MethionineHistidineAlanineTryptophanThreonineSTOP DNA Template Strand TACAGTGCGCACCTGAATT mRNA Strand AUGUCACGCGUGGACUUAA Protein MethionineSerineArginineLeucineAspartateLeucine DNA Template Strand TACTGCGAACGTGAATT mRNA Strand AUGACGCUUGCACUUAA Protein MethionineThreonineLeucineGlycineLeucine No Stop Completely Different!

15. Example  Cystic Fibrosis

16. You try it…  Write: THE BOY HAD THE FLU  Do two types of frameshift mutations:  Insertion of a single base  Deletion of a single base  In each case, how many amino acids would be affected during translation?

17. Mutations & Gene Expression  Which is more destructive? Point OR Frameshift Changes MANY amino acids MutationsPointSilentNot SilentFrameshiftInsertionDeletion Can be a “silent mutation” or only changes one amino acid

18. What Causes Mutations?  There are two main ways in which DNA can become mutated:  Mutagens: agents that cause changes in DNA:  Chemical exposure: pH, poisons, toxins, factory waste, pollution  Radiation: nuclear fallout, X rays, UV sun exposure  http://www.cnn.com/2014/10/29/health/oregon-brittany-maynard- video/index.html

19. Are mutations good or bad?  Both….  Mutations can lessen chances of survival  A mutation that makes a rabbit white instead of brown may make it easier to catch because it stands out in its environment.  Mutations can help chances of survival and increase genetic diversity in a species  Over millions of years, mutations have caused different colors in bear fur, and bears have evolved as different species in different environments (polar, forest)

20. Exhibition Step 2  Pick a mutagen  Research how it affects cells, and apply it to your selected cell  This is the conflict and introduction of the villain in your story