BIOL140A CSI Wildlife Lab Report

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Download this worksheet and save it as a WORD document, adding your name to the file name.

While doing the activity, fill out your downloaded worksheet and save frequently.

When you are finished, submit your report via Blackboard.

Go back to the elephant slide and find the link to the interactive CSI Wildlife tutorial. Watch the video on the starting page of this tutorial, then solve your first case.

Case One

Watch the video and read the introduction on the first slide (“The Crime Scene”).

1. Explain the goal of this case.

Go to the next slide (“How DNA Profiling Works”) and read through the Background section.

2. Look at the gel on the screen. What do the bands on the gel represent?

3. A scientist makes primers specific to a particular STR (short tandem repeat) 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.

4. What is the relationship between the size of a DNA fragment and the distance it migrates in the gel?

In the “Technique” tab, run the gel on the screen by pressing the Start button.

5. Which elephant (left or right) has both the largest and smallest fragments?

6. Approximately what sizes (in bp) are the largest and smallest fragments?

Read through the “Application” section

7. Look at the gel on the screen. For Marker C, are the two elephants shown homozygous or heterozygous? How do you know?

8. Why do you think scientists use multiple markers to identify individual elephants?

9. Name two properties of a good marker and explain why good markers are important.

10. Answer the questions in the review section. Summarize what you did to find out which elephant matches the ivory sample.

Did you solve the case?

Note: You are welcome to explore the frequency section, but it is not required for our course

Case Two

Watch the video and read the introduction on the first slide (“The Crime Scene”).

11. In Case One, you were looking for a match with an individual elephant. How does Case Two differ from Case One?

Go to the next slide (“Building a Reference Map”). Read through the Background, Technique, and Applications sections.

12. 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?

13. 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.

14. 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.

Go to the next slide (“Finding a Location”). Answer the questions until you reach the Eliminating North, East, or South section.

15. 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?

16. In the “Eliminating North, East, or South” section, which population did you eliminate, and which marker(s) helped you make this choice?

17. In the next section, which population did you eliminate, and which marker(s) helped you make this choice?

18. Could you imagine to do research similar to that of Dr. Wasser in your future? Why or why not?