Kayleigh RogersDrosophila Breeding in Reference to Mendelian Genetic LawIntroductionGenetics is the study of heredity and the variation of inherited characteristics. Humans and flies share at least 5,000 genes which make them model organisms. Model organisms are species that are studied to understand the biology of other organisms. Fruit flies share 75% of the genes that cause disease with humans, so scientists can learn about human genetics by studying fruit fly genetics (The Fruit Fly and Genetics). Fruit flies are most commonly used to study because they are low maintenance creatures and can easily be put to sleep also there size plays in because theyare small and don’t take up much room but they are still big enough to be able to examine underneath a microscope. The experiment that was performed was the look at fruit flies over a 2 week period of time. The first week the tubes were set up, we placed 3 male and 3 female larvae in the first tube which was the F1 generation of sex-linked cross. The second tube that was set upwas 3 male and 3 female also except it wasn’t sex-linked traits that were being looked at, but the unknown cross was being looked at. It was hypothesized that the observed results will not deviate significantly from the expected results and that they will follow Mendelian inheritance.MethodsDuring this 2-week experiment, the first week we just set up the tubes. We set up the sex-linked tubes which has both white eyed females and red eyed males. The second tube that was set up was the unknown cross which would determine the autosomal traits. To set the tubes up dry media is added to each of the two vials, about on spoon full, and then 10mL of water is added to each vial and mixed until the dry media is an even blue color. Once it has been mixed it is to sit in order for the mixture to set and solidify, then one to two grains of yeast is added to each tube. Now that the tubes have been set up, we took several different fly larvae to look at underneath the microscope in order to separate between male and female larvae. We separated out 3 male and 3 female for the first tube which would then be labeled sex-linked. Then we got the unknowncross flies and found 3 female and 3 males and added to the second tube and was then labeled unknown cross. During the second week, we observed the grown flies. We first added fly nap onto the fly nap wand and taped the flies to the bottom and then placed the fly nap wand in each of the vials to put the flies to sleep so that they could be examined. The vial was then laid on its side so that the flies would not drown in the media and then we waited to make sure all the flies had stopped moving before opening the container. Once the flies were asleep the first vial was poured on to a petri-dish. Once the flies in the first vial were observed they were placed into a flykill and then the second vial was put to sleep and exam just as the first vial, and once they were observed they were also put into the fly kill.ResultIt was observed that in the unknown cross did not follow the 9:3:3:1 ratio that was expected.Kayleigh RogersDiscussionSome limitations of this experiment is that the flies sometimes did not stay asleep, which caused some complications because when looking at them underneath the microscope it made it difficultto count the differences because some flies would be walking around. This experiment is significantly important to the field of biology because the flies’ small features it makes them easyto look at and study, and since the flies has many common genes with humans. Since the flies have many common genes with humans it is helpful when discovering and figuring out what genes cause what and what genes carry diseases. Some future experiments that could stem from this experiment would be to look at the genes of a different animal in comparison to human genes. With that experiment you could look at how some of the same genes could affect differentanimal as well as how different genes coincide the make-up of each animal.Kayleigh RogersWorks CitedAshburner, Michael. Drosophila. A laboratory handbook. Cold Spring Harbor Laboratory Press, 1989.Kohler, Robert E. Lords of the fly: Drosophila genetics and the experimental life. University of Chicago Press, 1994."The Fruit Fly and Genetics." The Fruit Fly and Genetics. N.p., n.d. Web. 02 Nov.