CSIWildlife-StudentWS1-CL (2).pdf - CSI Wildlife Analyzing Genetic Evidence Click Learn Student Worksheet INTRODUCTION This worksheet walks through Case

CSIWildlife-StudentWS1-CL (2).pdf - CSI Wildlife Analyzing...

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Unformatted text preview: CSI Wildlife: Analyzing Genetic Evidence Click & Learn Student Worksheet INTRODUCTION This worksheet walks through Case One and Case Two of the CSI Wildlife Click & Learn, except for the Frequency Primer section at the end of Case One. A separate document, entitled “Frequency Primer,” may be used for that section. In this Click & Learn, you will analyze genetic evidence to solve two cases of elephant poaching based on real events. PROCEDURE As you go through the Click & Learn, follow the instructions below and answer the questions in the space provided. CSI Wildlife Introduction Read the introduction and watch the opening video. 1. What is a keystone species? A keystone species is one that is vital to a healthy functioning ecosystem. Keystone species show great control over the community and diversity in an ecosystem. Many plants and animals within an ecosystem depend on the keystone species directly and indirectly. 2. Dr. Wasser states that approximately 50,000 African elephants are killed each year. According to the video, it is estimated that there are around 470,000 African elephants. If these numbers are correct, approximately what percentage of African elephants are killed each year? Show your work. 10.6% of the elephant population is killed during that year, if the population is 470000, and 50000 are killed. 50000 / 470000 = .106 .106 x 100 = 10.6% 3. In one or two sentences, summarize Dr. Wasser’s research and how it is being used to conserve elephants. Using the DNA to find out where the ivory comes from, Dr. Wasser is able to work with law enforcement to know where to focus their protection measures. Having law enforcement in concentrated area that have been known to be poached can hopefully help prevent illegal poaching. Case One Watch the video and read the introduction on the first slide (“The Crime Scene”). 4. Explain the goal of the case. The goal is to find where the tusks, that were found at the border, originated. 5. Look at the map on the screen. List the region or countries the majority of African elephants inhabit. Tanzania, Mozambique, and the Republic of the Congo. Ecology Revised December 2018 Page 1 of 4 CSI Wildlife: Analyzing Genetic Evidence Click & Learn Student Worksheet 1 Go to the next slide (“How DNA Profiling Works”) and read through the Background section. 6. Look at the gel on the screen. What do the bands on the gel represent? Each band between the agarose gel is one or two sequences of an STR. 7. DNA profiling is also called DNA fingerprinting. A common misconception about DNA fingerprinting is that the analysis has to do with actual fingerprints. Explain one similarity and one difference between a human being’s pattern of bands on an electrophoresis gel and a human fingerprint. A DNA profile on electrophoresis gel is unique to each individual, and can be used for identification, much like the uniqueness of a human's fingerprint. Read through the Technique section. 8. A scientist makes primers specific to a particular STR fragment. These primers are then used to amplify the STR fragment from 10 different elephants. Would you expect the fragments to be the same size in all the elephants? Explain your answer. I wouldn't expect the fragments to be the same size because the primer is only for a particular STR rather than a generic STR. 9. What is the relationship between the size of a DNA fragment and the distance it migrates in the gel? The bigger in size the DNA fragment is, the further it must migrate through the gel. Run the gel on the screen by pressing the Start button. 10. Which elephant (left or right) has both the largest and smallest fragments? Right 11. Approximately what sizes (in bp) are the largest and smallest fragments? Largest- 190 bp Smallest- 50 bp Read through the Application section. 12. Look at the gel on the screen. For Marker C, are the two elephants shown homozygous or heterozygous? How do you know? The base pair numbers from Marker C are different between the two elephants, making them heterozygous. 13. Why do you think scientists use multiple markers to identify individual elephants? I think scientists use multiple markers because the more markers, the higher chance it is to identify one individual. Ecology Revised December 2018 Page 2 of 4 CSI Wildlife: Analyzing Genetic Evidence Click & Learn Student Worksheet 1 Answer the questions in the Review section. 14. Show how you calculated the number of base pairs in the 10-repeat unit. 10x4= 40 40+9= 49bp Go to the next slide (“Finding a Match”) and answer the question, then watch the video on the “Case Solved” slide. 15. Name two properties of a good marker and explain why good markers are important. A good marker is one that is highly polymorphic and has a simple inheritance. These are important because they are faster and easier to detect. Case Two Watch the video and read the introduction on the first slide (“The Crime Scene”). 16. In Case One, you were looking for a match with an individual elephant. How does Case Two differ from Case One? In Case Two, I am looking for which population the ivory came from. Go to the next slide (“Building a Reference Map”). Read through the Background, Technique, and Applications sections. 17. For the gel in the Applications section, why does the lane for the ivory sample contain only two bands while the other lanes (A and B) have multiple bands? The ivory sample comes from one individual while the other sample comes from populations. 18. If an ivory sample has two alleles that are also found in a population sample, does that tell you with certainty that the ivory sample came from that population? Explain your answer. No, because you can't be certain of anything. This test is just an approximate. Answer the questions in the Review section. 19. If the scientist had collected 20 dung samples, would you expect more bands, fewer bands, or the same number of bands on the gel? Explain your answer. I would expect more bands because the more samples, the more alleles. Ecology Revised December 2018 Page 3 of 4 Click & Learn Student Worksheet 1 CSI Wildlife: Analyzing Genetic Evidence Go to the next slide (“Finding a Location”). Answer the questions until you reach the Eliminating North, East, or South section. 20. The three populations that were chosen for further analysis are geographically distant from one another. Why does this approach make more sense than choosing three populations that are geographically close to one another? populations closer together could have shared genetic alleles. 21. In the “Eliminating North, East, or South” section, which population did you eliminate, and which marker(s) helped you make this choice? I eliminated the North using Marker FH48 and Marker FH153. 22. In the next section, which population did you eliminate, and which marker(s) helped you make this choice? I eliminated the South using Marker FH60 and Marker FH129. Read through the last slide of Case Two (“Case Solved”). 23. By analyzing many more markers and all the populations, Dr. Wasser linked these seized ivory tusks to which country? Dr. Wasser linked the tusks to Tanzania. Ivory Trade Watch the video and read through the final slide (“Stopping Illegal Poaching”). 24. Name two reasons elephant populations are threatened. 50,000 elephants are being killed everyday and there is a high demand for ivory. 25. The introduction to the Click & Learn mentioned that elephants are a keystone species. Based on your knowledge of this term, explain in your own words why it is important to the ecosystems of Africa to save the elephant populations. It is important for Africa to do all it can to save these elephants because they are in great danger. These high demands fro ivory must stop because it is causing the deaths of several African elephants. As a keystone species they provide a great role in the ecosystem and they must be saved in order for Africa's wildlife to survive. Ecology Revised December 2018 Page 4 of 4 ...
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