In this experiment we set out to determine whether or not two different fruit fly crosses fit the 9:3:3:1 ratio, which is set up by the law of independent assortment. We did this by setting up a flask with first generation flies that gave rise to a second generation, which could be used to observe inheritance of phenotypes based on the parental phenotypes. We put the flies under a dissecting microscope to determine which phenotypes they exhibited, recorded the phenotypes in a table, used the data to determine the chi squared value, and compared our chi squared value to that of a table to determine if it actually fit the expected ratio. We found that in one cross this was true and that the other cross shouldn’t have fit it because it didn’t …show more content…
The fruit fly was used because they reproduce quickly, which allowed for us to see exactly what the outcomes of each cross were and the phenotypes were easily distinguishable. The objective of this lab was to determine whether or not the Drosophila crosses fit a 9:3:3:1 ratio using the Chi Squared Test. The 9:3:3:1 ratio simply means that nine are wild-type meaning they are normal; six exhibit one mutant and one normal character, three are normal for one trait the other three are normal for the opposite trait; one has both mutant phenotypes. Two different crosses were performed one between vestigial and sepia flies another between ebony and sepia flies. In the vestigial and sepia cross normal, wild-type, flies had normal eyes and wings; mutants which fit the second part of the ratio had vestigial wings and normal eyes while the other three had normal wings and sepia eyes; flies that fit that last part of the ratio had vestigial wings and sepia eyes. In the ebony and sepia cross wild-type flies had a normal body and normal eyes; mutants in the second part of the ratio had an ebony body and normal wings while the other three had a normal body and sepia eyes; flies that fit the last part of the ratio had an ebony body and sepia wings. We predicted that the Drosophila crosses would fit this
Variation in selection pressures on the goldenrod gall fly and the competitive interactions of its natural enemies
This information supports our hypothesis for the monohybrid cross, but it does not support our hypothesis for the dihybrid cross. In the monohybrid cross, it was expected that we would get a phenotype ratio of 3 plants with anthocyanin for every 1 plant with no anthocyanin. The plants with anthocyanin were easy to differentiate because of the purple color that is shown in the phenotype of plants with anthocyanin in them (Webb 2014). The results we observed were relatively close to this ratio, and the chi-square statist tells us that the monohybrid cross did follow mendelian inheritance patterns. In a different experiment done with Brassica rapa, it was found that when a set of plants with anthocyanin present were crossed with a set of the same species of plant but without anthocyanin present, the phenotypic ratio observed was 3 to 1 (Hayashi et al. 2010). This information just reinforces the idea that a monohybrid cross between Brassica rapa with anthocyanin and without anthocyanin does produce a F2 generation that follows Mendelian inheritance patterns with a 3 to 1 phenotypic ratio. The dihybrid cross we conducted was done with the anthocyanin gene, and the color gene. The dihybrid cross did not follow Mendelian inheritance patterns, so this leads us to believe there must have been a source
The purpose of our experiment was to test whether or not the Wisconsin Fast Plants, or Brassica rapa, followed the Mendelian genetics and its law of inheritance. First, after we crossed the heterozygous F1 generation, we created an F2 generation which we used to analyze. After analyzing our results, we conducted a chi-square test for for both the F1 and F2 generations to test their “goodness of fit”. For the F1 generation we calculated an x2 value of 6.97, which was greater than the value on the chi-square table at a p-value of 0.05 and 1 degree of freedom (6.97 > 3.84). This meant that we had to reject our hypothesis that stated there would be no difference between the observed and expected values. This showed us that the F1
Test 4: All three phenotypic frequencies saw a reduction in their number as the homozygote fishes saw a reduction in their number and were not able to pass on their alleles to create either their colored fish or a heterozygote. Both yellow and blue allele frequencies decreased by the same
Introduction: The purpose of this laboratory activity is to investigate the Hardy-Weinberg Law of Equilibrium using the fruit fly Drosophila melanogaster. According to the Hardy-Weinberg Law of equilibrium, allele frequencies should remain the same in large populations that do not experience gene flow, mutations, nonrandom mating, and natural or artificial selection. We will be studying the alleles that determine wing shape, either normal (wild type) wings or vestigial wings.
3 Leicht B. G., McAllister B.F. 2014. Foundations of Biology 1411, 2nd edition. Southlake, TX: Fountainhead Press. Pp 137, 163-168, 177-180,
We then allowed the larvae to hatch, and counted and recorded the total number of flies, the phenotype, and the sex. After taking down all this information this would allow us to perform a F1 cross, we made sure to examine the flies carefully since we needed virgin flies. We prepared a new vial with the a 1:1 ratio of medium and water. After recording the data of the F1 generation, and picking out the virgin flies for the crossing, and we killed of the rest of the flies using the oil method. After some time passed the F1 generation had larva in the vial. Once we noticed the larva we had to put the flies to sleep and collect the data. We then had to prepare another two new vials and medium and water. Carefully observing the flies and picking out three males and three female virgin flies to place into the new vial. Than killing of the other flies. After about a week we had the F2 generation. This was the most important generation, it was what we were looking for to allow us to observe and compare our experiment to Mendel’s experiment. We were looking for a 9:3:3:1 ratio with our flies. Using a basic Punnett square table and the crossing that we had accomplished our results should have looked like the following Punnett square.
Examining the Crosses Between Drosophila Fruit Flies Introduction The major topic of this experiment was to examine two different crosses between Drosophila fruit flies and to determine how many flies of each phenotype were produced. Phenotype refers to an individual’s appearance, where as genotype refers to an individual’s genes. The basic law of genetics that was examined in this lab was formulated by a man often times called the “father of genetics,” Gregor Mendel. He determined that individuals have two alternate forms of a gene, referred to as two alleles.
The purpose of this experiment is to conduct genetics studies using drosophila fly as the test organism. Scientists can study the basic biology that is shared by all organisms using a model organism, such as drosophila fly1. Drosophila fly, or more commonly known as fruit fly, has several qualities that makes it well suited for experimental genetics cross. First, fruit flies are low maintenance organisms. They are small in size (few millimeters long), so they occupy a small space and a lot of them can fit in one vial at the same time. They only require a media to feed on. In this lab, instant media was used, which is efficient as it only requires the addition of water to be used. This media contains ingredients that the fruit fly can feed one,
The exercise involved a series of ‘mating’ events resulting in 6 generations. Each mating event produced offspring with ‘possible’ newly inherited traits. The idea of ‘chance’ was included through simple coin tosses. Also, ideas of selection and mutations were introduced into the ‘gene pool’, which presented a deeper and more clear understanding of Mendelian inheritance and the Hardy-Weinberg equilibrium. Upon reaching the third generation, A B1 mutant allele was introduced to the blue locus-influencing fin shape and a G1 mutant allele was introduced to the green locus-influencing Mouth
17. Fruit flies normally have eight chromosomes. The diagram below shows the result of meiosis in three fruit flies to produce gametes with the number of chromosomes indicated. The male then mates with both female A and female B to produce three zygotes (1, 2, and 3).
The objective of this experiment is to determine what genes are responsible for the white-eye color in two strains of Drosophila melanogaster, known as the common fruit fly. Drosophila is used as the experimental organism for many reasons which include its small size, easy maintenance, short 10 day generation time, and a fully sequenced genome. The characteristics of the wild type, which is the most common phenotype found in nature, include brick red eyes, long wings, gray/tan body, and smooth bristles. Of course, there are mutations that occur that cause specific traits to deviate from the wild-type phenotype. These traits include wing length, bristle shape, body color, and eye color.
The F2 punnett square shows that there should not be a female fly that has apterous wing mutation. Our observed experiment showed that female flies are capable of forming in the F2 Generation. Therefore, the mutation is located on autosomal chromosomes. In trial 1, the p value is not significant. This could be due to the fact that the male to female ratio in the F1 generation was unequal. In trial 2, the p value is significant and likely due to chance. The probability error is between 1 % and 5%.
In my third year at Michigan State, I was enrolled in a class called Research in Biology. The goal of this course was to determine if there was a genetic marker to tell three different species of Rhagoletis flies apart due to their shared phenotypes and the infestation of apples, which became quarantined when one species was found in the orchards. If the other two species were found in the orchards, they would do no harm and the apples would be safe. Using their mitochondrial genomes, we ran gel electrophoresis and Nanodrop analysis and sent the DNA to Michigan State’s genomic core lab to be processed by Illumina. After getting the data back, our lab used a development node called Trimmomatic to eliminate adapter sequences, poor quality control bases, and ambiguous bases.
Conclusion for class di-hybrid cross: The p value 0.779 is in the non-significant range in the chi square table. The null hypothesis is therefore correct. Sepia eyes and vestigial wings in the flies is a mutation in the genes that is not linked meaning it is a product of independent assortment.