Drosophila Flies Lab Report

Title:
Determining Phenotypes of Crosses Between Drosophila Flies
Ameena Ahmed, Ishana Fleurant, Aleksandra Drozdziel, and Chelsea Kornfeld.

Abstract
The purpose of this experiment is to determine phenotypes of 2 separate crosses between Drosophila flies and compare the outcome to the expected results, which should fit the 9:3:3:1 ratio, set up by the law of independent assortment. A vial with a set of 3 male flies with specific characteristics were mated with 3 female flies with distinct characteristics as one of the two crosses; the characteristics were reversed in a separate cross between 3 males and 3 females, each gender with distinct characteristics. The first generation flies of each cross were individually mated to give rise to a second generation, which were then used to observe inheritance of phenotypes based on the parental phenotypes. The observed results were used to collect data, which was used to determine the chi squared value and then compared to the expected ratio of 9:3:3:1, based on the

It was used because of its rapid rate of reproduction, The objective of this lab was to determine whether the two crosses conducted fit the expected results of a 9:3:3:1 ratio, which could be done using the Chi Squared Test. The 9:3:3:1 ratio meant that the phenotypes of the F2 offspring would occur in a nine: three: three: one ratio- 9 would be wild-type or normal, 6 of the offspring would have one normal and one mutant characteristic and lastly one of the offspring would be a mutant for both phenotypes. Two distinct crosses were conducted during this experiment: one using red eyed, ebony bodied males and white eyed, brown bodied females as the F1 generation and the other cross using white eyed, brown bodied males and red eyed, ebony bodied females. Our hypothesis, or prediction was that crossing offspring from the F1 generation, or the F2 progeny would fit the expected outcome of a 9:3:3:1 ratio as