Question 1
The experiment to determine whether the trait is dominant or recessive would be conducted by performing a test cross of the drosophila melanogaster. Fruit flies with a trait that is already described as homozygous recessive say the ebony-bodied color if the phenomenon being investigated is the fruit flies’ body color would be crossed with the fruit flies having the unconfirmed trait. The fruit flies would be put in test tubes with a base comprising of yeast and some nutrients for the fruit flies to feed on and lay eggs. The fruit flies would be observed and the dead ones removed while the larvae would be allowed to develop and, when fully developed, microscopically examined for the particular trait under investigation.
The test cross could lead to two different outcomes. Firstly, is that all the offspring could phenotypically express the particular trait under investigation (Khan Academy, n.d.). Such an outcome would exhibit that the trait is dominant and thus its expression in all the organisms. The trait would be described as homozygous dominant genotype and phenotype. The cross could also lead to half of the offsprings (50%) phenotypically expressing the trait under investigation while the other half phenotypically expressed the trait exhibited by the parent with the homozygous recessive trait (Khan Academy, n.d.). Such an outcome would confirm that the trait under investigation is recessive. The trait would be termed as a heterozygous genotype.
Delegate your assignment to our experts and they will do the rest.
Question 2
Various traits possessed by fruit flies make them model genetic organisms. One of the notable traits possessed by fruit flies that makes them useful in genetic studies is their short life span, about two weeks, which allows them to mate and produce lots of offspring at a time (Dutchen, 2018; Tolwinski, 2017) increasingly). The huge number of offspring provides a genetic pool for scientists to conduct their research. Fruit flies also happen to have several chromosomes within their cells that allow for viewing genetic changes such as mutations quite easily (Dutchen, 2018). Fruit flies also possess some unique similarities to humans, making them suitable genetic research organisms for human diseases. An example is the fruit flies genome being 60% homologous to humans (Mirzoyan, 2019). About 75% of the genes attributable to human diseases happen to have homologs in flies (Mirzoyan, 2019). The use of fruit flies in genetic research requires a low maintenance budget as the organisms easily survive on a mixture of cornmeal, sugar and yeast. Another advantage of fruit flies in genetic research is that it is relatively easy to differentiate males from females.
Humans fail to meet some of the characteristics of fruit flies, such as the short generation time, easy viewing of the chromosomal changes and low maintenance costs.
References
Dutchen, S. (2018, April 2). Why the fly? Harvard Medical School. https://hms.harvard.edu/news/why-fly
Khan Academy. (n.d.). Introduction to heredity review (article) . https://www.khanacademy.org/science/high-school-biology/hs-classical-genetics/hs-introduction-to-heredity/a/hs-introduction-to-heredity-review
Mirzoyan, Z., Sollazzo, M., Allocca, M., Valenza, A. M., Grifoni, D., & Bellosta, P. (2019). Drosophila melanogaster: A model organism to study cancer. Frontiers in Genetics , 10 . https://doi.org/10.3389/fgene.2019.00051
Tolwinski N. S. (2017). Introduction: Drosophila-A Model System for Developmental Biology. Journal of developmental biology , 5 (3), 9. https://doi.org/10.3390/jdb5030009
