Drosophila melanogaster are often used as a model organism in laboratories due to the many advantages that the organism provides: short generation time, sexual dimorphisms, cost effectiveness and easiness to maintain, amongst others. The generation time of Drosophila is around 9 – 11 days, and phenotypes in men, such as sex combs, heavily pigmented abdomen, and shape of abdomen and size, makes of Drosophila melanogaster an effective organism to study. In Drosophila melanogaster, the males do not go through crossing over during meiosis, which allows certain genes to be easier to track since only parental genotypes are passed from female parent to their male offspring. A crossover is the basis of genetic information exchange, which occurs when homologous chromosomes pair up on the basis of sequence similarity in meiosis I and chiasmata is formed between two chromatids (Hochwagen 2008). Closely
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To do this, we must determine pattern of inheritance, whether they are located in autosomal or sex-chromosomes and if they are sorting independently of each other. If all the male progeny from the F1 generation posses the mother’s phenotype, the trait would be sex-linked. If the phenotypes of the F2 generation are different from the expected ratios, the genes can be said to be sorting independently. Pattern of inheritance is determined upon analysis of observed phenotypes from F1 and F2 generations by knowing if the genes are located in an autosomal or sex- chromosome and assessing the dominance patterns. The Chi-Square analysis is a statistical test, which purpose is to find the difference between expected and observed data. The formula for this test is: ∑ (observed results –expected results)2 / expected results. It allows us to determine if the difference in numbers is the result of chance or if its due to an underlying biological
To do this, we must determine pattern of inheritance, whether they are located in autosomal or sex-chromosomes and if they are sorting independently of each other. If all the male progeny from the F1 generation posses the mother’s phenotype, the trait would be sex-linked. If the phenotypes of the F2 generation are different from the expected ratios, the genes can be said to be sorting independently. Pattern of inheritance is determined upon analysis of observed phenotypes from F1 and F2 generations by knowing if the genes are located in an autosomal or sex- chromosome and assessing the dominance patterns. The Chi-Square analysis is a statistical test, which purpose is to find the difference between expected and observed data. The formula for this test is: ∑ (observed results –expected results)2 / expected results. It allows us to determine if the difference in numbers is the result of chance or if its due to an underlying biological