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Bio 9B: Monday, 4.25.11 Title: Connecting Genetics and Evolution: Cystic Fibrosis Case Study

Bio 9B: Monday, 4.25.11 Title: Connecting Genetics and Evolution: Cystic Fibrosis Case Study. Homework: Complete through analysis Question 1 for CF Case Study (different than assignment sheet) Do Now: What comes to mind when you hear the word “EVOLUTION” Today’s Objectives:

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Bio 9B: Monday, 4.25.11 Title: Connecting Genetics and Evolution: Cystic Fibrosis Case Study

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  1. Bio 9B: Monday, 4.25.11Title: Connecting Genetics and Evolution: Cystic Fibrosis Case Study • Homework: • Complete through analysis Question 1 for CF Case Study (different than assignment sheet) • Do Now: • What comes to mind when you hear the word “EVOLUTION” • Today’s Objectives: • Determine an organism’s genotype and phenotype by analyzing their DNA sequences

  2. Introduction to Evolution PHA Biology 9 Moretti/ Dickson

  3. EVOLUTION • Genetic changes in a species or population over time

  4. Connecting Genetics and Evolution:Cystic Fibrosis Case Study • Purpose: • Discuss mutations and their possible effects • Learn about the effects of mutations that cause cystic fibrosis • Analyze DNA sequences to determine if and what kind of mutations exist • Whole Class Work: • Read the Background Information and Supporting Information • Paired Work: • Complete the Pre-Activity Questions • Determine the genotypes and phenotypes of 4 people for the CFTR protein to identify whether or not they have Cystic Fibrosis • Individual Work: • Read the below article, “Cystic Fibrosis protects against tuberculosis”, from the magazine New Scientist. Then answer the following questions

  5. Connecting Genetics and Evolution:Cystic Fibrosis Case Study Figure 1. Chest Radiograph of CF Diffuse Interstitial Disease • Image: http://www.eradimaging.com/site/article.cfm?ID=327: Reprinted with permission from LearningRadiology.com. Case of the Week Archives—2003. Cystic Fibrosis. Available at: http://www.learningradiology.com/toc/tocsubsection/tocarchives2003.htm. Accessed January 28, 2008.11

  6. Connecting Genetics and Evolution:Cystic Fibrosis Case Study • Purpose: • Discuss mutations and their possible effects • Learn about the effects of mutations that cause cystic fibrosis • Analyze DNA sequences to determine if and what kind of mutations exist • Whole Class Work: • Read the Background Information and Supporting Information • Paired Work: • Complete the Pre-Activity Questions • Determine the genotypes and phenotypes of 4 people for the CFTR protein to identify whether or not they have Cystic Fibrosis • Individual Work: • Read the below article, “Cystic Fibrosis protects against tuberculosis”, from the magazine New Scientist. Then answer the following questions

  7. Bio 9C: Tuesday, 4.26.11Title: Cystic Fibrosis, Tuberculosis and Evolution • Homework: • Complete/ Revise Analysis Question 3 after today’s discussion. • In your Notebooks: • Actively Read 16.1 with and put your reading notes in your notebook. THEN, complete questions 1, 2, 4, & 5 at the end of the chapter. Put these questions in your notebooks. • Do Now(s): • On next three slides (clicker questions) • Today’s Objectives: • Determine an organism’s genotype and phenotype by analyzing their DNA sequences • Explain how mutations can be passed on and why this is important in evolution • Explain why certain allele can become more common in certain populations

  8. Reviewing Background Info & HW

  9. The CFTR protein is: 25 • A gene • A channel in cell membranes • A chloride ion • An amino acid 16

  10. Connecting Genetics and Evolution:Cystic Fibrosis Case Study Figure 1. Chest Radiograph of CF Diffuse Interstitial Disease • Image: http://www.eradimaging.com/site/article.cfm?ID=327: Reprinted with permission from LearningRadiology.com. Case of the Week Archives—2003. Cystic Fibrosis. Available at: http://www.learningradiology.com/toc/tocsubsection/tocarchives2003.htm. Accessed January 28, 2008.11

  11. Did you complete the genotype/ phenotype chart by analyzing the DNA sequences for all of 4 people? 25 • Yes • No 19

  12. Did you try to finish all of the reading and try to complete up to question 1? 25 • Yes • No 19

  13. Which of the children in the problem definitely has CF? 25 • Fred • Wilma • Barney • Betty 18

  14. Reviewing CFTR Genotypes

  15. DNA Analysis for the CFTR Protein

  16. Tuberculosis and the Evolution of the CF Gene

  17. CF and Evolution • Read the article, “Cystic fibrosis gene protects against tuberculosis” • Respond to question 3

  18. Based on the reading, why may people of European decent have a higher frequency of Cystic Fibrosis 25 • The CF gene originated in Europe and only Europeans can pass it on to offspring • Having 1 copy of the CF gene may provide resistance to sickle cell anemia • Having 1 copy of the CF gene may provide resistance to tuberculosis • The CF gene does not have a higher frequency in Europeans 0 • Objectives for Class: • Determine an organism’s genotype and phenotype by analyzing their DNA sequences • Explain the evolutionary connection between cystic fibrosis and tuberculosis

  19. Evolutionary Terms and Vocab Block 2

  20. Some New Evolution Terms • Population • Group of individuals from the same species that interbreed • Gene Pool • All the genes and all of their alleles in population • Relative Frequency • The proportion of one allele in the whole gene pool • Evolution (on a population scale) • Any change in the relative frequency of alleles over time • One allele becomes more common, another becomes less common • Change in a population NOT change in an individual • Fitness • The ability of a particular genotype to reproduce and pass on its genes to the next generation • Objectives for Class: • Use actual evidence to explain how the four principles of natural selection shape the evolution of organisms

  21. Evolution Notes: Micro-Evolution • Small-scale • Changes in a population’s gene pool over time • Caused by natural selection and/or genetic drift Example: CF allele becomes more common in European populations because it protects against tuberculosis • Objectives for Class: • Use actual evidence to explain how the four principles of natural selection shape the evolution of organisms

  22. Evolution Notes: Macro-Evolution • Large-scale, often over a very long time • Branching of one species into two species • Leads to the idea that all species share a common ancestor Example:Evolution of whales from four-legged land mammals Micro-evolution leads to Macro-evolution • Objectives for Class: • Use actual evidence to explain how the four principles of natural selection shape the evolution of organisms

  23. How Do Populations Evolve? Natural Selection: • Certain genotypes/phenotypes are more “fit” than others, and pass on more of their genes to the next generation • Over time, those “fit” genes become more common in the whole population because they are more helpful for survival and reproduction

  24. Complete HW • In your Notebooks: • Actively Read 16.1 with and put your reading notes in your notebook. THEN, complete questions 1, 2, 4, & 5 at the end of the chapter. Put these questions in your notebooks.

  25. Bio 9B: Wednesday, 4.27.11Title: Evidence for Natural Selection • Homework: • Pass Cystic Fibrosis Case Study to the left • Write a paragraph in your notebook that explains each of the following terms and how they relate to each other: • population • gene pool • alleles • evolution in populations • natural selection • Do Now(s): • Next slide • Today’s Objectives: • Explain how natural selection can cause an allele to become more common in a population’s gene pool over time.

  26. Did you try to finish all of the reading and try to complete all of the 3 questions? 25 • Yes • No 20

  27. Based on the reading, why may people of European decent have a higher frequency of Cystic Fibrosis 25 • The CF gene originated in Europe and only Europeans can pass it on to offspring • Having 1 copy of the CF gene may provide resistance to sickle cell anemia • Having 1 copy of the CF gene may provide resistance to tuberculosis • The CF gene does not have a higher frequency in Europeans 16 • Objectives for Class: • Determine an organism’s genotype and phenotype by analyzing their DNA sequences • Explain the evolutionary connection between cystic fibrosis and tuberculosis

  28. Recap and Review: Cystic Fibrosis and Tuberculosis • Recessive Genetic Disorder • Result of a gene mutation in the CFTR protein • Numerous types of mutations – most common is deletion of 1 amino acid at Codon 508 • Evidence suggests people who are homozygous recessive and heterozygous are resistant to tuberculosis • TB bacteria need a nutrient that these people do not make • When TB killed 20% of Europeans from 1600-1900, people who are heterozygous for CF gene survived to pass on the gene • Allele persists, despite people who are homozygous recessive not reaching adulthood • Objectives for Class: • Determine an organism’s genotype and phenotype by analyzing their DNA sequences • Explain the evolutionary connection between cystic fibrosis and tuberculosis

  29. Evidence for Natural Selection Finches on the Galapagos Islands

  30. Galapagos Finch Investigation

  31. Evidence for Natural Selection: Finches on the Galapagos Islands • Objectives for Class: • Use actual evidence to explain how the four principles of natural selection shape the evolution of organisms

  32. Bio 9B: Thursday, 4.28.11Title: Review of Natural Selection • Homework: • Complete Natural Selection Review Packet • Do Now: • Next Slide – Log in with clicker • Today’s Objectives: • Explain the process of natural selection • Apply the principles of natural selection in order to analyze a variety of examples

  33. Starting in 1954 commercial fishers were paid by weight, rather than by the individual fish for pink salmon. The fishers used the type of net that selectively catches larger fish. Which of the following is the most likely effect of this technique on salmon populations over the next 20 years? The average body size of the salmon population increased significantly. The average body size of the salmon population decreased significantly. The average body size of the males increased and the females stayed the same. The average body size of the males stayed the same and the females increased. 21 of 25

  34. Agenda Complete Galapagos Finch Investigation (25 min) (enrichment extra credit if completed early and all other assignments are complete) Principles of Natural Selection review and second case study

  35. Galapagos Finch Investigation

  36. Evidence for Natural Selection: Finches on the Galapagos Islands • Objectives for Class: • Use actual evidence to explain how the four principles of natural selection shape the evolution of organisms

  37. Recap and Review: Evidence for Natural Selection in Galapagos Finches • Drought causes declines in the food supply between 1976-1978 • Variety of seeds declines and only tough seeds with thick shells are left. • Only those finches with thicker beaks can eat. Finches with narrower beaks can’t eat and die. • Result:Relative frequency larger beak sizes increase, because birds with bigger beaks survive and reproduce. The alleles for larger beak size have greater fitness! • Objectives for Class: • Use actual evidence to explain how the four principles of natural selection shape the evolution of organisms

  38. Agenda Principles of Natural Selection review and second case study

  39. More Evidence for Natural Selection: Hummingbird Populations • Scientists studying natural selection in Hummingbird Populations in Ecuador: http://www.pbs.org/wgbh/evolution/library/11/2/e_s_4.html • Objectives for Class: • Use actual evidence to explain how the four principles of natural selection shape the evolution of organisms

  40. Principles of Natural Selection • “Selection” is • different survival and reproduction of individuals with different genotypes • Natural selection involves… • Genetic variation between individuals in the species and/or population • More offspring are born than can survive • Competition/struggle for survival for limited resources • Variation between individuals that makes some better able to survive and reproduce than others • This variation is heritable/genetic (can be passed on) Result: Over many generations, the genotypes that are better able to survive and reproduce become more common in the population.

  41. Summarizing Natural Selection in the Hummingbird Case Study • In your notebooks: • Take five minutes to summarize how the 4 principles of Natural Selection are demonstrated in the hummingbird case study you just watched. • Use specific examples from the film to describe each principle • Four Principles: • Genetic Variation • Over-production of Offspring • Struggle for Existence • Differentiated Survival

  42. Bio 9B: Monday, 5.2.11Title: Review of Natural Selection • Homework: • Reading from Section 16-3: • Read pages 404-405 and take notes on: • What is speciation? • What is reproductive isolation? What are some different ways that populations can be reproductively isolated? • Read pages 408-409 and take notes on: • What are the steps of speciation? • Do Now: • Next Slide – Log in with clicker • Today’s Objectives: • Explain the process of natural selection • Apply the principles of natural selection in order to analyze a variety of examples

  43. 1. Which statement is the BEST description of the theory of evolution by natural selection? 5 • When environmental conditions are challenging for a population, some individual organisms mutate in order to get the traits that will help them survive the best. • The organisms that are the strongest and fastest always survive the longest. • In populations, some individuals have combinations of genes that allow them to survive and reproduce better, which causes these gene combinations to spread through the whole population over many generations. • Humans evolved from a species of apes because humans have longer life spans than apes. 0

  44. Review Principles of Natural Selection • “Selection” is • different survival and reproduction of individuals with different genotypes • Natural selection involves… • Genetic variation between individuals in the species and/or population • More offspring are born than can survive • Competition/struggle for survival for limited resources • Variation between individuals that makes some better able to survive and reproduce than others • This variation is heritable/genetic (can be passed on) Result: Over many generations, the genotypes that are better able to survive and reproduce become more common in the population.

  45. Two Sources of Genetic Variation • Mutations • Any change to a DNA sequence • Rare • Sometimes harmful, sometimes helpful • Mutations to egg or sperm = passed on to offspring • Mutations to body cells = not passed on (but can cause CANCER) • Gene Shuffling • Meiosis divides the genetic info and fertilization recombines it • 23 pairs of chromosomes = 8.4 million different combinations of genes! • Crossing Over during meiosis increases the number of different combinations of alleles • Objectives for Class: • Explain the process of natural selection • Apply the principles of natural selection in order to analyze a variety of examples

  46. More Evidence for Natural Selection: Antibiotic Resistance in TB Bacteria • Bacteria populations can evolve too! • Let’s watch and see how people influence evolution in bacteria… http://www.pbs.org/wgbh/evolution/library/10/4/l_104_09.html In your Notebook: • How does the TB bacteria experience natural selection. • How did population of bacteria change over time, and why? • How is this similar to the Hummingbird and Finch case studies? • Objectives for Class: • Explain the process of natural selection • Apply the principles of natural selection in order to analyze a variety of examples

  47. Clicker Review of Natural Selection

  48. 2. Which of the following factors has the greatest effect on whether the new coat color will become more common in the mouse population? 5 • Whether abundant food is available in the grassland • Whether the new coat color allele is dominant or recessive • Whether the rate of reproduction in the mouse population is stable • Whether the new coat color allele increases the survival and reproduction of mice in their environment 0

  49. 3. The long tail feather trait is maintained in the barn swallow population because, compared to males with a shorter tail feather, males with a longer tail feather are more likely to: 5 • Build a large nest • Produce offspring • Migrate each winter • Escape from predators. 0

  50. 4. Which biological concept is being illustrated in the diagrams of the lizard population? 5 • Polygenic traits • Natural selection • Sex-linked inheritance • Silent mutations 0

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