1. Drosophila Simulations Activity
© David Faure, InThinking

2. Learn to identify the fly phenotypes and the male and female flies, click “Find out about”

3. Hover over each of the flies

4. Morgan’s first experiment

5. Make a prediction about the second cross.

6. Morgan’s White Eyed Male Breeding Experiments

7. Select white eyed male and wild type female

8. Carry out a cross

9. Click “Cross”

10. F1 offspring flies appear, ready for sorting
F1 offspring flies appear, ready for sorting. Drag each fly into a box, top right.

11. Notice the green tick – if you sort correctly

12. Final totals / 25 for first cross

13. Click “cross” again for a second run, note first totals and sort the second set of flies.

14. Add your results to the chi squared test

15. Can females be white eyed?

16. F1 x F1 - cross the heterozygous flies – drag one of each fly to the “New parent” boxes

17. Click Cross – to see F2 offspring

18. Sort the flies once again for F2 results.

19. Choose a white eye male and a heterozygous wild type female, drag them to the “New parents” boxes

20. Notice the white eyed females

21. Add your results to the chi squared test

22. Morgan hypothesized that the eye colour trait was connected to the sex chromosome.

23. More evidence of gene linkage

24. Chose a female wild type and a scarlet eyed and ebony body male for the next experiment

25. Notice the F1 flies are all wild type (but heterozygous)

26. Choose a male and a female as new parents

27. Click “Cross”, then sort the F2 flies
Click “Cross”, then sort the F2 flies. Notice the low number of recombinants !

28. A final chi-square test of goodness of fit

29. Linkage notation

30. A new type of punnet square for linkage