Drosophila Autosomal and Sex-Linked Cross The idea of the project was to experiment breeding Drosophila Melanogaster (fruit fly) to figure out if certain genes of that species were sex linked or not (autosomal). A mono-hybrid cross and di-hybrid cross was performed. For the mono-hybrid cross, white eyed female and red eyed male were placed in one vial for them to reproduce. For the di-hybrid cross, red eyed and normal winged flies and sepia eyed and vestigial winged flies were placed in their vial to reproduce. In the mono-hybrid cross the results expected were within a 1:1:1:1 ratio. Expected results similar to the expected desired null hypothesis proposed with what the F1 parental generation breeds. The potential results would have had to have been within the ratios of 9:3:3:1. The results were clear and allowed the null hypothesis to be correct. The white eyed gene in the fruit flies is sex linked. Sepia eyes and vestigial wings are not sex linked and are examples of independent assortment. Introduction Genetics has given us important results with regards to knowing why certain organisms and their expressions are the way they are and how some expressions are suppressed due to those particular expressions being recessive. The reason is because genetics is the study of genes and the effects of it to organisms. Genes are expected to give offspring hereditary similarities to the parent. However, this was not known and Gregory Mendel asked himself what was passed on by parents to their offspring that is the basis for similarity. Mendel would go on through experiments with pea plants to answer short questions. The answers were short as well as to say that the passing of characteristics from parents to the offspring is throug... ... middle of paper ... ...e 9:3:4:1 but it did not seem to be significant in the probability. • Conclusion for class mono-hybrid cross: The p value 0.222 was in the non-significant range in the chi square table. The null hypothesis was therefore correct. The colors of the eyes are sex linked due to the equality in the amount of phenotypes given to both male and female. • 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. Bibliography Cain, M. L., Urry, L. A., & Reece, J. B. (2010). Campbell Biology. Benjamin Cummings. Phelan, J. (2011). What Is Life? A Guide To Biology with Physiology. New York: Peter Marshall.
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
revealed that three of the fourteen samples were were homozygous while the other eleven were
Miller, K. R., & Levine, J. S. (2010). Miller & Levine biology. Boston, Mass.: Pearson.
3 Leicht B. G., McAllister B.F. 2014. Foundations of Biology 1411, 2nd edition. Southlake, TX: Fountainhead Press. Pp 137, 163-168, 177-180,
The fruit fly, or the Drosophila melanogaster, was used in this experiment to study patterns of inheritance. It only takes a fruit fly 14 days to develop from an egg to an adult and then 12 hours before they become reproductive, so these factors made the fruit fly a good species to study, because we had enough time to do crosses. We were investigating the patterns of inheritance in the eye color and the wings. The wild type flies had red eyes and full wings, while the mutant phenotype had brown eyes and no wings. We also had to study the sexes of the flies. The male flies had darker abdominal tips and sex combs on both of their forearms. For the results, my group had predicted as follows:
In Drosophila (fruit flies) genes can be linked or non-linked. Linked genes are genes that are close together on the chromosome so they often appear in pairs. Non-linked genes are not close together and Mendel’s law of Independent Assortment states that each trait is equally likely to slow up. The purpose of this lab is to find out if the genes of purple eyes and black bodies are linked in Drosophila. Flies are good for this experiment because they display a number of different traits and they mate quickly. If the eye and body color genes are linked in Drosophila then the F2 generation will not have a 9:3:3:1 ratio because the genes are on the same chromosome and cannot independently assort when they are crossing over. Since linked genes often appear in pairs, it is likely that there will be many more flies that are wild-type for both genes or have purple eyes and a black body than a combination of these genes. If the eye and body color genes are not linked in Drosophila then the F2 generation would have a 9:3:3:1 ratio because the law of independent assortment states that each gene has an equal chance of occuring.
Miller, K. R., & Levine, J. S. (2010). Miller & Levine biology. Boston, Mass: Pearson
Rantala, M. J., and Roff, D. A. 2006. Analysis of the importance of genotypic variation,
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
The experiment consisted of putting blind mutants (ninaB360d or 1118) in daylight and dark environments to asses their courtship behavior towards intact females and decapitated female flies.
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
Can we expect that the correlation between CNP genotypes (hybridization intensities) and CNP phenotypes is reasonably high?... ... middle of paper ... ...10) Line 158, In case the copy number is the same (c=b), the equation would give zero. Is this the right one? 11) Line 171, SNP phenotypes -> CNP phenotypes?
This data had a probability of 0.05 according to the chart. The 0.05 probability indicates this data was not very accurate compared to the expected ratio. The female Chi squared was 20.41 which provided a low probability of 0.001. This data was not very accurate at all since the Chi squared was very high and did not follow the ratio closely. The F1 x F1 cross, that used the two parents female sepia and male dumpy, had a male Chi squared of 13.93 which showed a probability of 0.001. The probability showed poor data since it did not fit well with the expected 9:3:3:1 ratio and was lower than the 0.05 cut off. The female Chi squared was 15.13 and showed a probability of 0.001. This data was also not very accurate since it strayed from the expected ratio. Both male and female showed the same expected ratio indicating no different in gender for these genes. The reciprocal crosses also made no impact on the progeny data since the ratios were 9:3:3:1 for both sets of F1 x F1 crosses. Usually it is not a good idea to treat reciprocal test crosses as the same cross using Drosophila because male Drosophila do not cross over while females
more than half the variation was found to be due to heredity. Among these traits were
A fly with just the “promoter-Gal4” is known as the driver line. The “UAS-GFP” alone in fly allows us to determine what specific foreign gene is introduced into the fruit fly’s genetic makeup. In this case, the “UAS-GFP” alone in flies allows us to determine that GFP is the incorporated foreign gene into the fruit flies genome, but it is not actively expressed. A fly with just the “ UAS-GFP” in known as the responder line. This allows for the crossing over of both lines of flies to show an expression of a specific gene at a specific tissue in their offspring and this allows to determine the effects of both components in the fruit