Research Paper about Drosophila Melanogaster
Drosophila melanogaster was experimented on to allocate phenotypic characteristics in means of observing. By placing anesthetized Drosophila a four-week trial was conducted to distinguish ebony body distributions within the Drosophila generations. Data stated helped to analyze and determine a mode of inheritance.
Introduction
Drosophila melanogaster has been used in various experiments to help understand genetic mutation and how it can help find greater advances in medicine that can be proven to offer a greater stimulation in the genetic makeup. Since Drosophila is inexpensive and produces about 100 eggs within ten days makes it a cooperative organism that can easily be mutated to re self-cloning. For example, if a gene is meant to be essential to development to a particular cell type, neighboring cells would send signals to hormone deficits and accommodate the needs. Thus, asking what cells in an organism are wild-type to permit the normal development of the cell type. However, if the “cell type” is without an essential gene then, the organism is considered a mutant presuming that it is not needed, inferencing that the organism is to be either heterozygous or recessive, but not homozygous. Knowing so within the Drosophila experiment the files were anesthetized to observe sex and phenotype to determine a mode of inheritance.
One easy way to differentiate between the two, males are smaller than females. But to get into detail, a wild-type female or male is tan like-colored has a proportioned wingspan or body length. In contrast, a mutant female or male can have different characteristics, such as altered wing structure, vertical wings, or curled wings. Even abnormal body color- yellow or ebony( dark like), along with having white yes, is also one to identify a mutant fruit fly.
A the end of the three-week trial the mode of inheritance was concluded to be autosomal recessive and the null hypothesis states there is no difference between that of the observed and expected values. The alternative null hypothesis states there is a difference between the observed and expected values.
Method and Materials
For the first two weeks of the experiment, observing Drosophilas’ sex and phenotype were the primary focus. The only difference was during week one the parental generation was observed, while in week two the F1 generation was observed. Upon beginning the experiment, four vials were presented each to present a different mode of inheritance. Pertaining to this experiment vial B was given and the ebony body was the phenotype to focus on. To begin the experiment, the vial was held downward to avoid any flies becoming stuck to the medium. While holding the vial downward a CO2 blowgun was used to sedate the flies. As the tip of the blowgun is being inserted make sure it does not pass the cotton, instead leave the tip between the cotton and the entrance o the vial. In doing so, the flies will surrender within a couple of seconds. After being fully sedated the Drosophila were placed on a CO2 plate to ensure constant sedation, where then the Drosophila were observed under a stereoscopic microscope. While viewing them from the microscope, the data was adequately written down to help with the further investment towards the continuing experiment. Then, carefully and moderately, we concluded our research and proceeded to put them back within the vial with a thin paintbrush provided. Week three was invested in observing the sex and phenotype of the organism as well, however, this time statistics were produced using a chi-square test to help verify whether or not the hypothesis was conclusive.
Results
During the week for the parental generation, the table for the parental generations demonstrates that a total of seven Drosophilas were studied, and out of seven, five were female, and two were males. Four females and one male were wild types indicating typical characteristics of the body. In contrast, one female demonstrated a lighter pigmentation, and the one male had a darker appearance, suggesting that it was a mutant. In the F1 generation table, a total of sixteen fruit flies were observed. Ten of them were female, and the remaining six were males. From there, nine out sixteen were wild-type females, and one out sixteen were wild-types mutant. Not only did the mutant female have an abnormal body color she also displayed white-colored eyes. Finishing up the F1 generation, six out of sixteen were male wild types while only one was a male mutant by demonstrating an ebony body.
In the F2 study, only six were observed, where three females were wild types, and two were mutants; one displayed the lighter body color and white eyes, and the other had peculiar orange-eyed color. In contrast, only one male wild type was diagnosed from the bunch. In the F2 generation, the total sum observed was not very high compared to the previous generation. For this particular generation, there was balance in the values of normal to ebony, which could be almost equal. Both phenotypes could result dominant or recessive. Knowing so a ratio of 1:1 was valued, where x2= 0.66 and compared to the critical value the hypothesis is stated to be true.
Lastly, in the F2 generation figure(in groups) the results demonstrate that the phenotype with a normal body has a greater chance of passing along the later generations, however, a handful of the offspring also showed to have an ebony body. By performing the chi-squared test, a calculated value of 0.1 with a degree of freedom of 3 proved to show that the original hypothesis is also acceptable. To sum it all in four figures the hypothesis was deemed to be conclusive and showed for the most part a few more opinions could still be debatable, despite the calculated values.
