Fruit Fly Drosophila melanogaster experiment AP Biology 2018

Fruit Fly Drosophila melanogaster experiment AP Biology – 2018 Lab Dihybrid Cross and Sex-linked cross

Find a buddy for the fruit fly experiment 1. Go pick up two vials, two foam caps, two stickers and place them on your vial in the center of your vial 2. Watch your teacher demonstrate how to make a vial with media Make a vial with media, don’t forget to put only about 4 -5 grains of yeast on the top of the media. 3. Now pick up a booklet of fruit flies and read the pages indicated until your teacher has you come up to get your flies and put them in your jar. Before you put them in your jar. Look at them under the microscope. Make sure to write the NUMBER of each of your males and females on your jar and which have white eyes and which have wild(red) eyes.

Take a booklet on Fruit flies and read/take notes on 1. Page 8, and 9 Life cycle and anesthetizing – HOW LONG DO YOU LEAVE IN WAND of fly nap? IMPORTANT – sleep not death 2. Page 11 sexing and look at back of pamphlet 3. Look at page 15, 16 and 17 on phenotypes 4. Skim through the rest of the booklet to look at types of crosses and other information about Drosophila

Let’s look at a fruit fly cross x P 1 Wild eye, vestigial wing F 1: all wild Sepia eye/wild wing F 2 are all: 9: 3: 3: 1

Get your fruit flies and your booklet • Take out a sheet of paper to record your data for your fruit flies • Male red Male white Female white Create a chart and use tally marks. Female red

Sex-linked cross Wild eyes vs. White eyes Parents F 1 Cross What is expected? X R XR or XRY x x X r. Y X r Xr

Male vs Female

Determining sex Female notice clear bottom, larger Male Dark end On bottom

Class Results of Red eyed fem and white eyed males Group Name Parents were Cross of Red eyed females with white eyed males X R x X r. Y Red eye female Jade/Noah/ Sean Abby/Reece Liz/Skylar Trinity/Raygen Red eye male Wk 1 16 Wk 2 Wk 1 24 17 Wk 2 20 14 15 18 26 79 24 33 56 30 13 17 15 White eye female White eye male Wk 1 Wk 2

Class Results of Red eyed females and white eyed males Parents are cross of White eye female and red eye male Xr. Xr x XRY/Xr. Y apparently white eye males got in here Group Name Red eye White eye female Red eye male female Wk 1 Wk 2 Brandon/ 1 Jordan Eleanor/ Klay/ Lauren 1 10 2 8 4 10 2 22 White eye male Wk 1 Wk 2 20 1 17 17

Dihybrid cross F 2 results Tally your marks then share results Red eyes, wild wing Red eyes, vestigial Sepia eyes, wild wing Sepia eyes, vest wing Day 1 Day 2 Day 3 Reece & Abby 55 8 7 22 4 2 20 0 2 1 Brandon Jordan 34 5 14 11 7 7 9 4 5 3 1 0 Trinity Raygen 18 5 10 12 6 3 3 1 0 0 Klay Lauren 20 Eleanor 1 9 10 3 2 6 1 2 3 1 1 Liz &Skylar 35 8 3 19 4 2 12 4 3 0 1 0 Noah Sean Jade 49 12 7 19 6 5 17 3 4 7 3 1 Group Name

Write up for Fruit flies: Focus on dihybrid but discuss the X-linked cross in your analysis/results, conclusion. I. Problem/Question: Will a dihybrid cross of sepia/vg mutant parents crossed with wild result in the expected ratio of 9: 3: 3: 1 and meet the null hypothesis. II. Hypothesis: Yours – might be the NULL hypothesis. III. Materials: IV. Procedure: V. Data tables/GRAPH, VI. Analysis/Results: Show your math for Chi Square VII. Conclusion: Follow writeup directions for Conclusion(3 paragraph approximately. )

Now Conduct the Analysis: To determine null hypothesis value take the total number of flies and divide by 1/16, 3/16, 9/16 to get the expected

2018 RESULTS add all your x 2 values Phenotypes Wild Red eyes/ normal wings Red eye Vg wing Sepia eye Vg wing observed expected o-e (o-e)2 X 2

How many degrees of freedom? #phenotypes – 1 = degrees of freedom, look under the. 05 column CHI-SQUARE DISTRIBUTION TABLE Accept Hypothesis Reject Hypothesis Probability (p) Degrees of Freedom 0. 95 0. 90 0. 80 0. 70 0. 50 0. 30 0. 20 0. 10 0. 05 0. 01 0. 001 1 0. 004 0. 02 0. 06 0. 15 0. 46 1. 07 1. 64 2. 71 3. 84 6. 64 10. 83 2 0. 10 0. 21 0. 45 0. 71 1. 39 2. 41 3. 22 4. 60 5. 99 9. 21 13. 82 3 0. 35 0. 58 1. 01 1. 42 2. 37 3. 66 4. 64 6. 25 7. 82 11. 34 16. 27 4 0. 71 1. 06 1. 65 2. 20 3. 36 4. 88 5. 99 7. 78 9. 49 13. 38 18. 47 5 1. 14 1. 61 2. 34 3. 00 4. 35 6. 06 7. 29 9. 24 11. 07 15. 09 20. 52 6 1. 63 2. 20 3. 07 3. 83 5. 35 7. 23 8. 56 10. 64 12. 59 16. 81 22. 46 7 2. 17 2. 83 3. 82 4. 67 6. 35 8. 38 9. 80 12. 02 14. 07 18. 48 24. 32 8 2. 73 3. 49 4. 59 5. 53 7. 34 9. 52 11. 03 13. 36 15. 51 20. 09 26. 12 9 3. 32 4. 17 5. 38 6. 39 8. 34 10. 66 12. 24 14. 68 16. 92 21. 67 27. 88 10 3. 94 4. 86 6. 18 7. 27 9. 34 11. 78 13. 44 15. 99 18. 31 23. 21 29. 59

One more helpful hint as you writeup your lab • When reporting chi square data use the following formula sentence…. With is and degrees of freedom, my chi square value , which gives me a p value between % %, I therefore my null hypothesis. • This sentence would go in the “results” section of your formal lab. • Your explanation of the significance of this data would go in the “discussion” section of the formal lab.