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Bio 9C: Monday, 4.25.11 Title: Connecting Genetics and Evolution: Cystic Fibrosis Case Study. Homework: Complete up to Analysis Question 1 for CF Case Study Do Now: What comes to mind when you hear the word “EVOLUTION” Today’s Objectives:
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Bio 9C: Monday, 4.25.11Title: Connecting Genetics and Evolution: Cystic Fibrosis Case Study • Homework: • Complete up to Analysis Question 1 for CF Case Study • 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
Introduction to Evolution PHA Biology 9 Moretti/ Dickson
EVOLUTION • Genetic changes in a species or population over time • Objectives for Class: • Determine an organism’s genotype and phenotype by analyzing their DNA sequences
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
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
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
9C: Room 107 Front of Room Crystal Jamesly Amando Carla Marie Sophie Asarel Julian Amanjot Obayanna Joe Jhon Anthony Lilliana Jason Karen Kendra Marcus Rockens Meryem Brunyr Christine Jonathan Garlyn
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
The CFTR protein is: 25 • A gene • A channel in cell membranes • A chloride ion • An amino acid 19
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
Did you complete the genotype/ phenotype chart by analyzing the DNA sequences for all of 4 people? 25 • Yes • No 19
Did you try to finish all of the reading and try to complete up to question 1? 25 • Yes • No 19
Which of the children in the problem definitely has CF? 25 • Fred • Wilma • Barney • Betty 0
CF and Evolution • Read the article, “Cystic fibrosis gene protects against tuberculosis” • Respond to question 3
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.
Bio 9C: Wednesday, 4.27.11Title: Introduction to Evolution Notes and Concepts • 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- sign in your clicker! • Today’s Objectives: • Explain how natural selection can cause an allele to become more common in a population’s gene pool over time.
Which of the children in the problem definitely has CF? 25 • Fred • Wilma • Barney • Betty 22
Did you try to finish all of the reading and try to complete all of the 3 questions? 25 • Yes • No 22
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 14 • Objectives for Class: • Determine an organism’s genotype and phenotype by analyzing their DNA sequences • Explain the evolutionary connection between cystic fibrosis and tuberculosis
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
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
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
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
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
Revisit Sickle Cell – Micro Evolution • A Case Study of Sickle Cell Disorder… http://www.pbs.org/wgbh/evolution/library/01/2/l_012_02.html • How is this an example of micro-evolution?
Synthesizing Concepts • 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 • When done, swap with a neighbor to get feedback on your paragraph
Bio 9C: Thursday, 4.28.11Title: Evidence for Natural Selection: Finches on Galapagos • Homework: • Pass the CF Investigation to the left if late • Complete the Galapagos Finches Analysis Questions • Do Now(s): • Next slide – log in with your clicker • Today’s Objectives: • Use actual evidence to explain how the four principles of natural selection shape the evolution of organisms
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. 22 of 23
Agenda Galapagos Finch Investigation (enrichment extra credit if completed early and all other assignments are complete) Principles of Natural Selection review and second case study
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
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
Agenda Principles of Natural Selection review and second case study
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
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.
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
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
Bio 9C: Monday, 5.2.11Title: No Class • Homework: • Do Now: • Today’s Objectives:
Bio 9C: Tuesday, 5.3.11Title: Review of Natural Selection • Homework: • Complete Natural Selection Review Assignment • 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
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
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.
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
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
Which of the following best explains the increase in drug-resistant TB bacteria? 5 • The bacteria that are resistant to the drugs mate with each other to produce super-resistant bacteria that have twice as many copies of the resistance genes. • TB bacteria only infects people who are already malnourished and sickly, and the bacteria draws strength from the infected people in order to become resistant to their medicines. • When anti-TB drugs are taken in low doses, the drugs kill the most susceptible bacteria but don’t kill the more resistant bacteria. The more resistant bacteria reproduce and pass on their resistance genes so that the whole population becomes resistant to the drugs. • When a patient begins taking anti-TB drugs, the bacteria mutate in order to become resistant and fight off the drugs. 0
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