Fruit Fly Lab Report Essay

Abstract The different factors that contribute to the eye pigmentation of Drosophila melanogaster are based on proteins that are likely to influence in the fly's eye pigmentation. The experimental procedure was done to learn more about Mendelian Law of Segregation and to determine whether or not two different fruit fly crosses for the 3:1 phenotypic ratio. In this study, the lab group examined the eye pigmentation of Drosophila melanogaster’s under a dissecting microscope to determine the phenotypes that the second generation would exhibit. The predictions made throughout the experiment was, the flies will show no eye color change, and any other effect will be due to the existence of a mutation in the genes. Alternative hypothesis made throughout

The process consisted of counting the second generation flies and observe the phenotype in this case eye pigmentation. F1 had red/brown eye color. The following table demonstrates the phenotypic ratio obtained for an F2 generation.

Table 1.1 Phenotypic ratio of second generation D. melanogaster.


The table above, note that the phenotypic ratio of monohybrid is 3:1, but the genotype for the generation is 1:2:1.

Table 1.2 Quantitative and qualitative data of second Drosophila melanogaster. After approximately three weeks, a total of 62 fruit flies were obtained for the second generation. There were 16 males that expressed the recessive allele (w) and 14 that expressed the wild type (+). Note that out of 32, cero females were carriers of the white gene.

A chi-square test was done on the results obtained for the observable trait of the second generation flies Drosophila melanogaster in order to determine the rejection of acceptance of the null (Ho) hypothesis and the alternative (Ha) Hypothesis. The following data table 1.3 shows the calculations obtained for the color pigmentation.

Table 1.3 Chi-Square analysis of F2 generation