Abstract The objective of this lab to, develop an understanding of the inheritance patterns observed in a fruit fly. For this experiment we used Drosophila melanogaster as a model organism due to its short life cycle, small size, and its virtual inexpensiveness. Drosophila melanogaster commonly known as the fruit fly used in this experiment provided experimental data that was in agreement with the laws of segregation and independent assortment proposed by Gregor Mendel. We began with F1 generation set of flies consisting of dihybrid males and females. The F1 generation consisted of all heterozygous genotypes. By examining the F2 offspring’s at the end of the lab and using the Chi-square test to test our hypothesis we were able to determine …show more content…
We then added a few grains of yeast to each vial (not exactly the same). We then added sufficient fly water (1%propionic acid) to hydrate and compress the flakes. As the fly water was added the flakes turned bright blue. We then cut our given 2x2inch plastic nets in half and forming a cross we pushed then down the tube, making sure it doesn’t touch the bottom of the vial touching the food. We then were handed our F1 generation flies. We then realized that the F1 flies that we had received were dihybrid and “will produce approximately 50-70 adult flies over a span of 10-12 days” (Carolina.com, Drosophilia, “living F1 ap X se cross”). As we put the F1 vial into the freezer to temporary immobilize the flies we simultaneously prepared our anesthetizing chamber. Labeling our vials we then began to anesthetize our flies for transportation. Made very small hole into the bottom of the anesthetizing chamber then removed the bottom lid and placed a very finite amount of flynap onto the cotton, then closed the lid and placed the stopper back on. Then we removed the flies from the freezer within 4 minutes and gently tapped a few of them into the anesthetizing chamber and closed the lid. After 3 minutes we removed the lid and placed the immobilized flies under the light scope and began to separate male from female. Males had a darker end than females making separation easy. Placing two males and two females into each vial at a 90 degree angle to ensure the flies don’t stick to the food on the bottom and die. We then placed the vials on their size into a dark and closed space. My group met multiple times through this husbandry process to reposition the vials after a few days and exam for signs of F2 larva. After one weeks without result we decided to rehydrate the food and wait a few more days. Checking back we saw larva in the vials, then removed the F1 generations to
The motivation of this lab report is to use Mendel’s Laws of Inheritance to analyze and predict the genotypes and phenotypes of an offspring generation (F2) after knowing the genotypes and phenotypes of the parent generation (F1). The hypothesis for this experiment is that the mode of inheritance for the shaven bristle allele in flies is autosomal recessive in both male and female flies.
Through further research, I have learned that this vase “depicts the heroes Achilles and Ajax playing a board game” (Two-Handled Jar with Achilles and Ajax).
Introduction: The intention of this lab was to gain a better understanding of Mendelian genetics and inheritance patterns of the drosophila fruit fly. This was tasked through inspecting phenotypes present in the dihybrid crosses performed on the flies. An experimental virtual fly lab assignment was also used to analyze the inheritance patterns. Specifically, the purpose of our drosophila crosses is to establish which phenotypes are dominant/recessive, if the traits are inherited through autosome or sex chromosomes and whether independent assortment or linkage is responsible for the expressed traits.
It was decided that there would be 80 vestigial flies and 20 wild type flies to total to an initial population of 100 drosophila. Next, the flies were anesthetized flies using Fly Nap. The flies were counted out to reach desired ratio, sexing the flies making sure there are equal amounts of males and females to be sure there is ample individuals to allow successful mating. The fly’s food was prepared by taking a frozen rotten banana, cutting it in half, mashing up the banana meat, and mixing yeast into it. The
The results of this cross was that there were thirty eight wild-type females and thirty five wild-type males. Therefore there were seventy three wild-type flies. There were sixteen no-winged mutant males and eleven no-winged mutant females. Therefore there was a total of twenty seven no-winged flies produced in this cross. The observed phenotypic ratio of wild-type flies and no-winged mutant flies was 2.7:1 (winged: no-winged).The predicted phenotypic ratio if the no-winged mutation was autosomal recessive would be 3:1 (winged: no-winged). The χ2 value obtained for this cross was 0.213. The p value that was obtained for this cross was
I believe that I qualify for one of the scholarships the Wilson class of 1945 is awarding because I am a hardworking student who commits to all opportunities and advantages presented to me. I am very thankful that the dedication and diligence I have applied to my education and extracurricular activities over the past four years have afforded me with the opportunity to attend Charleston Southern University where I have been awarded one the highest university scholarships of $52,000. This university scholarship has allowed me to see my dreams and goals in a new light for the first time and believe that they are truly possible and that there are people who believe me and my dreams just as my family does. Receiving this scholarship from the class
The vials were separated into males and females. Five male and female from each vial were put in a specific vial ending up with 20 flies in one vial. It was made sure the group had enough flies; any extra flies were distributed among the groups to assure everyone has the correct amount of flies for each genotype. The exact number of flies for all four phenotypes ( male (+/+), male (e,e), females (+,+), and female (e,e)) were used. Any remaining flies not need by anyone were put cake into the cultured vial where they came from.
It would be expected that the mutant F1 flies would be heterozygous for the allele responsible for the grounded trait. If two F1 flies were mated, the percentage of flies that would be expected to be wildtype in the F2 generation would be 25% mutants given that the mutant allele (ap) is predicted to be recessive and, leaving 75% to be wildtype (ap+).
we said goodbye and placed them in the fly morgue. We allowed the F2 larval
8. Third week: Remove the F1 flies from the vials and place them into the morgue. The F2 generation are the eggs and /or larvae in the vial. Place the vial in a warm place.
The genotype of the parental genotypes where chosen by looking if there was a difference in the data. If there was a linkage in the sex or in the gender. Since, there were none, the two allele for each mutant was used but for the men we use the apterous to be wild and wild on the eyeless for female. When we perform the dihybrid hypothesis cross shown in Table 4 we obtain a ratio to be 9:3:3:1. The result of the dihybrid cross show that the predicted values where excellent however when the Chi-Square was made the obtain value was high which makes the data not to fall into the
We then kept the vial with the juvenile Drosophila for another 2 weeks in the same conditions as above and found that the F1 generation had hatched and laid eggs of their own. We then decanted the F1 generation into alcohol to kill them and kept them aside to score. The vial containing the new generation F2 of Drosophila was then kept for use in a further experiment.
The parents are both homozygous. The homozygous dominant would represent the wild type. And the homozygous recessive would represent the other fly parent of a different strain. The F1 generation would consist of 100% Wild Type but they would all be heterozygous in carrying the recessive gene.
From the beginning of the project, the insects proved to be little buggers, no pun intended. Within the first week, the flies manifested as anesthesia resilient. Even after half an hour in the freezer or twenty minutes in the fly equivalent of a gas chamber, they were still buzzing around unaffected. We joked that the flies possessed the “I’m not dead yet” gene I had once read about. Maybe they had evolved over the years, because they simply would not die, let alone fall asleep long enough for me to examine them. Yet, ironically, as soon as it came time to breed my little winged friends, many of them mysteriously fell to their death.
For our first generation (F1) of flies we chose to cross apterous (+) females and white-eye (w) males. We predicted that the mutation would be sex linked recessive. So if the female was the sex with the mutation then all females would be wild type heterozygous. Heterozygous is a term used when the two genes for a trait are opposite. The males would all be white eye since they only have one X chromosome. If the males were the sex that had the mutation then all the flies would be wild type but the females would be heterozygous.