INTRODUCTION TO DROSOPHILA
Name: ______
Drosophila melanogaster, the “black bottomed dew loving” fly, has been important model organism. Initially, it was the work horse of genetics, and like C. elegans it later became important in study of animal development (the discovery of homeotic genes).
Procedure & Questions
1. Acquire two anesthetized flies, one of each gender. Use your naked eyes and a dissecting microscope to describe major differences that you can determine between the two flies. Sketch the two flies below and identify their distinguishing characteristics. Hypothesize their gender as well.
2. Use the internet to determine the characteristics that distinguish male and female fruit flies and record the information below. Was your hypothesis correct?
Male - ______
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Female - ______
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3. Next, acquire a Petri dish with live fruit flies and determine the type of mutant strain represented. Describe the character of each mutant – what makes it different than the wild type.
Mutant 1______
Mutant 2 ______
Mutant 3______
Mutant 4______
Mutant 5______
4. Next, surf to the following website, navigate to the introduction on gene naming, and explain how genes are named.
5. Then, navigate back, view the gene names by organisms, scroll until you get to the Drosophila genes, and pick the three that you think are the most clever and that can be shared in a zoology classroom. Explain why you like each.
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Homework
Surf to the following website and search for information on the Nobel Prize winning work of Thomas Hunt Morgan (Physiology and Medicine 1933)
6. For what work did Morgan win his Nobel Prize?
Navigate to the link on “His Legacy”, and answer the following questions.
7. What special mutant fly did Morgan discover?
8. Why was he skeptical of Mendelism and/or why did he ridicule explanations of contemporary breeding results?
9. Why did he choose the fly to complete his studies?
Next, surf to the DNAi timeline at select the appropriate time from, find Morgan’s work, click to watch Morgan and the Genetics of Fruit Flies, and answer the following questions.
10. Diagram the first two crosses that they performed along with their results. Use a colored pencil/pen to note the eye color and use your knowledge of the differences between male and female flies to draw them different in the diagram.
11. What was the most curious result of these crosses?
12. Complete the punnett square that explains these results.
13. How are female white eyed fruit flies produced?
Surf back to the Nobel website at:
14. What type of inheritance had Morgan discovered with the white eyed fruit flies?
15. With the work of his students Sturtevant and Bridges how did he finally overcome his skepticism of the work being done on Mendelian inheritance?