Inheritance Patterns of the Fruit Fly
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:
X-linked
X= dominant allele X’= recessive allele
XX x XY X-linked Dominant
This would produce 100% of the dominant phenotype in females.
This would produce 100% of the dominant phenotype in males.
XX’ x XY X-linked Recessive
This would produce 100% of the dominant phenotype in females with 50% carrying the recessive trait.
This would produce 50% of the dominant phenotype in males and the other 50% of males would express the recessive trait.
Autosomal Dominance
A= dominant allele a= recessive allele
This will result in a 100% dominant phenotype.
Methods
We had received 2 cultured bottles and added a few grains of yeast and some cool water. We had received wild type flies to sex and had to set up crosses with them. After anaesthetic that we used to put them to sleep, we emptied them onto a piece of white paper and viewed them under a dissecting microscope one by one to determine their individual sexes. We then had set up a vial with 5 wild type males and one female, checking the vial periodically for any change. Our next step was to make up a vial of mutants. Once both vial were set up, all we had to do is wait for an appearance of eggs or larvae. By the completion of week 2, we started to see larvae, which meant that we had to take the initial flies out so not to disturb our counts. We had discarded the females and put the wild type and mutant males into new vials. The bottles were checked periodically for the formation of females.
This meant that we had to reject our hypothesis for the dihybrid cross which stated that there would be no difference in the observed and expected values. This showed that the F2 generations did not follow Mendelian genetics because it did not express a 9:3:3:1 phenotypic ratio. In both our F1 and F2 generations, we had to reject our hypotheses because they did not follow the Mendelian genetic inheritance pattern show by our results above. Because both the F1 and F2 generations of Brassica rapa failed to follow the Mendelian genetics inheritance pattern, there could have been some biological errors that cause this to happen. An example of this is that maybe not every single plant got the exact same amount of water or same amount of sunlight, causing the plants to grow differently and therefore deviate from the Mendelian’s law of inheritance. To prevent this from happening in the future, what could have been done was measure out the amount of water each plant got rather than just watering each plant casually. Also, for the amount of sunlight, steps could have been taken to ensure that each plant would get the exact same amount of light and not get different amounts just because of where they were
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
79%, were heterozygous. We concluded that it is possible to examine small amounts of DNA by
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.
reproduction of superior genes through heredity by controversial means. This idea is based on the
To distinguish between males and females, a microscope and magnifying glass was used to analyze several different factors. Body type was one characteristic looked at because while females consisted of a lot of body segments and a pointed abdomen, males have fewer segments with a black, rounded abdomen. The difference in body sizes were also a factor to separate between sexes. Females were comparably larger than males who also had sex combs on their legs. There were several other distinguishable markings used in order to separate the flies based on their sex. Once the flies were separated based on sex, the number of male to female were counted to make sure there was an equal ratio between the two. The F1 generation male and female groups were divided into groups to equally mate. The mating process began by acquiring empty vials, sponges to cover the vials, and labels to label each vial. The vials were labeled with the name of the individuals and the type of cross, either monohybrid or dihybrid cross. Once each vial was labeled, they were all filled with
If one wanted to know their chance of carrying or having the disease creating a punnet square could help determine that. A normal person without Albinism or the presence of the allele melanin can be represented by capital “A” and another allele that represents the lack of melanin will be represented with lower case “a”. Since Albinism is an autonomic recessive disease, this means a person with a homozygous recessive gene will have the disease. Both parents must be heterozygous dominant and carry the allele; they will have a 25% chance of having a child with albinism and a 70% chance of having a child carrying the disease. If one parent is heterozygous that still carries the flawed gene and the other parent is homozygous dominant there will be a 50% chance their child will carry the disease but wont have a child with Albinism.
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
Mendel’s law of segregation states that offspring receive only one of two alleles of a gene from the parent (Brooker et al. 2014). This means that utilizing a monohybrid cross where each parent has both a dominant allele of a gene and a recessive allele, that by producing offspring of these plants, a predictable outcome of trait inheritance should be observed (Brooker et al. 2014). This experiment investigated the inheritance of anthocyanin in Brassica rapa.
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 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.
middle of paper ... ... avour of "purity of the race" idea, but they understand how it worked. Blond hair and blue eyes are recessive genes. Two brown-eyed people can give birth to a blue-eyed child, but two blue-eyed people cannot give birth to a brown-eyed child. Dark skin and dark hair are also dominant genes, so because of evolution, it must mean that the ancestors of humanity had dominant genes.
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.
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
...ary part in genotypes of potential interest that human geneticists breeders, as well as evolutionary geneticists are investigating. However, although we have the capability to unravel experiments that the founders of quantitative genetics would have never imagined, but their basic, un-computational machinery that they developed is most easily adaptable to the latest analyses that will be needed. We are far from ‘letting-go’ molecular biologists from the mathematical techniques/systems, because this age in respect to genomics has been forced into accepting gratitude due to the major importance of quantitative methods as opposed to the new molecular genetics. As geneticists tend to map molecular variation as well as genomic data, quantitative genetics will be moving to the front position because of its relevance in this age of rapid advancement in molecular genetics.