Inheritance of drosophila from each allele from 4 of the 5 tests shows a 3:1 dominance, favouring the wild type (+) phenotype. The wild type (+) phenotype was tested and experimented on against the other eye colour phenotypes, including wild type, brown, purple, sepia and white. It was easily evident that every F1 on each test was solely wild-type dominant. Since, for example, +/+ with SE/SE can only make +/SE which can be discovered using a Punnett grid, making the first generation only heterozygous, while making + the dominant trait. The second generation of offspring, however, is affected as the combination can create heterozygous and homozygous offspring, being affected by both phenotypes of + and SE. This is not entirely random, though, since a 3:1 ratio is maintained, with + being the most dominant phenotypes from all tests. The significance of this data is gathered through the chi-squared test.
The chi-square test results displayed that almost all tests maintained …show more content…
Specific tests showed that the predicted results differed slightly to the observed results. For the wild type/wild type cross, there was a 100% chance of the wild type phenotype, so the gender ratio of 1:1 (or 50% to 50%) was implemented instead, showing a chi-square distribution value of 0.1674 and an observed difference of 8. The other tests showed an approximate 3:1 ratio of alleles against the F2 population, the largest distance between the observed and expected data was shown in the Wild type/White test, with a chi-square distribution of 0.7488 and an observed difference of 13, while still maintaining a good fit. The wild type/white test also showed some rather interesting data, with there being no female white-eyed drosophila, yet there was male white-eyed and female wild-type. This could have been a result of chance or proof showing that the white-eyed phenotype was not