Dihybrid Cross in Fruit Flies
... According to this law, the F2 generation in a dihybrid homozygous cross should yield a 9:3:3:1 phenotypic ratio. ... The purpose of this study was to determine the modes of inheritance demonstrated by specific crosses of the common fruit fly, Drosophila Melanogaster. ... According to a ƒÓ2 analysis, Model Cross II supported the null hypothesis, which suggested this particular cross included traits governed by the Law of Independent Assortment. According to statistical analysis, the data of Model Cross I refuted the hypothesis, giving a ratio expected for a set of sex-linked genes. ... The Law of Independent Assortment can be confirmed by crossing a homozygous dominant individual and a homozygous recessive individual for two traits in a dihybrid cross. ... The purpose of this experiment is to determine the mode of inheritance of specific mutations of the fruit fly (Drosophila melanogaster). The study of fruit flies is especially beneficial due to their short life cycle and small size. ... The null hypothesis for both crosses is that the genes of the fruit fly are independently assorted. ... If they are independently assorted, then by making two dihybrid crosses, one with wild-type females and recessive yellow body/white-eyed males, and the other with wild-type males and recessive sepia-eyed/dumpy winged females, both F2 generations will show a 9:3:3:1 ratio. ... The first step in the experiment was to prepare four model cross culture vials. ... After the vials were created, two of the vials were labeled as Model Cross I and two vials as Model Cross II. The second part of this experiment required the use of cultures of four variants of the common fruit fly Drosophila Melanogaster. ... In order to make the transition of fruit flies from their culture vials into the model crosses, we made use of knock out bottles and FLYNAP, an anesthetic used to sedate the flies. Knockout bottles are containers the fruit flies fly into in order to anesthetize them with FLYNAP. The anesthetized flies are then observed to determine the sex.