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
In order to figure out the genes responsible, there are several other factors that must be determined. These factors include the number of genes involved, if each gene is x-linked or autosomal, if the mutant or wild-type allele for each is dominant, and if genes are linked or on different chromosomes. Proposed crosses include reciprocal crosses between the pure-breeding mutants of strains A and B with the wild-type will help determine if the genes or sex-linked or autosomal, in addition to which alleles are dominant (8). Another proposed cross includes complementation crosses between pure-breading mutants from strains A and B to determine if one or two genes are involved (8). Furthermore, testcrosses between F1 progeny and pure-breeding recessive mutants from strains A and B, which will help determine if genes are linked on the chromosome or if they assort independently (8). These proposed crosses are shown in the attached
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
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 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
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.
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.
In this experiment, Mendelain Models are observed. The purpose of the experiment is to understand how traits are passed from one generation to the other as well as understanding the difference between sex linked and autosomal genes. One particular trait that is observed in this experiment is when a fly is lacking wings, also known as an apterous mutation. In this experiment, we will determine whether this mutation is carried on an autosomal chromosome or on a sex chromosome. The data for this experiment will be determined statistically with the aid of a chi-square. If the trait is autosomal, then it will be able to be passed to the next generation on an autosomal chromosome, meaning that there should be an equal amount of male and
In our genes, multiple different alleles determine whether one person will have a certain trait or not. Alleles are what make-up our genotypes and in this lab, we wanted to determine the genotypes of our class in the two loci: TAS2R38 and PV92. The TAS2R38 locus codes for a protein that involves the bitter taste of PTC; the gene determines whether or not a person will taste the PTC paper as very bitter or no taste at all. People with the “T” allele are tasters while those that are homozygous recessive (tt) are non-tasters. The taster locus can be found chromosome 7.3 The two different alleles present in the could be due to the effect of evolution and natural selection because the same can be found in chimps.4 The PV92 locus does not code for any protein but rather involves an Alu element that is 300-bp long. A person with the “+” allele would have the Alu element making that sequence longer while those with the “-“ allele don’t have the element and would have a shorter sequence. This locus can be found on chromosome 16.3 There are multiple Alu sequences found among primate genomes but there are human specific sequences such as the one found on the PV92 locus.1 In the experiment, student DNA was collected from cheek cells and PCR was used to target the loci and amplify the region of DNA. In the taster gene, after amplification, a restriction digest was performed to differentiate between the two alleles. The digest was able to show differentiation because those with the “T” allele would have two bands from gel electrophoresis and those with “t” will have one band because the restriction enzyme doesn’t cut it. For the PV92, we were able to distinguish between the alleles due to the added length of the Alu element. Those...
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. An individual can me homozygous dominant (two dominant alleles, AA), homozygous recessive, (two recessive alleles, aa), or heterozygous (one dominant and one recessive allele, Aa). There were tow particular crosses that took place in this experiment. The first cross-performed was Ebony Bodies versus Vestigle Wings, where Long wings are dominant over short wings and normal bodies are dominant over black bodies. The other cross that was performed was White versus Wild where red eyes in fruit flies are dominant over white eyes.
When trying to understand genetics Mendel 's laws are a very big part of it. Mendel 's two laws help us understand and analyze genetic crossings. In our experiment we used drosophila melanogaster flies, a common fruit fly. This was perfect to understand and visualize how the laws take effect. Mendel stated that during the process of genetic crossing; two alleles are formed which then separated to form gametes, which would appear in fertilization. In our experiment we accomplish a cross that determined different eye and body colors. By using the Chi-Square test, we were able to test our results. Our groups hypothesis stated the number of flies from the F2 generation would accommodate Mendelian Genetic Ratio of 9:3:3:1. Our Chi-Square test results
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
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.