Biological Phenotype And Genetic Function Of The Purple Gene

The basis of genetics were established by Gregor Mendel, an Augustinian monk in the mid to late 1800’s. Through the observations from cross-pollinating pea plants, Mendel was able to discover the basic laws of inheritance. Years later genetics would be studied on a multitude of organisms, some more than others. Drosophila melanogaster or the common fruit fly has been studied in depth for its great advantages, such as size, reproduction rate, ease of care and inexpensive room and board.

To set up this experiment, two twenty-five gallon aquariums, 3 petri-dishes, 200 flies, rotten bananas, and yeast were used. The bananas chosen to be an accelerant for the growth of the yeast and were frozen so they would be easier to cut. The yeast was used because the drosophila melanogaster prefer this as a food source.  The vestigial and wild type flies were sexed (to determine their sex), sorted, and counted.  An initial population size of 100 total flies was decided so that it would be easier to determine the phenotypic percentage of the total population. Fly paper was placed in one of the sets of cages to impose a method of natural selection as well as the sexual selection which is being solely tested by the other set of cages.

melanogaster, leaving B and D to be our mutants. Before crossing our populations, we made not of each one’s phenotype in order to see how crossing them would affect their phenotypes: Population B flies had no wings and red eyes, population D had full wings and black eyes and population G had full wings and red eyes. We expected the resulting phenotypes to be some sort of combination, revealing which traits were dominant. However, what we did not expect was the abnormal mutant that arose in a couple of our populations.

This discovery was made when Morgan was working at Columbia and one day, while observing a male fruit fly, he noticed that instead having bright red eyes as any normal Drosophila melanogaster would, this particular insect had white eyes. Morgan questioned the cause of the color of that fly to be different and wondered how this trait was acquired. In order to answer his questions, Morgan proceeded to do simple breeding analyses with the white-eye fruit fly. This experiment began with a test cross between the white-eyed fly with normal red-eyed females. The results in the first generation was all red eyes. This was shown through the use of Punnett squares. However Morgan didn’t stop there, he took the male and females from the first generation and test crossed them again. This time, the second generation resulted with some flies with the white-eyed trait along with some red-eyed trait. Morgan noticed that the only white-eyed trait however occurred only in the male fruit flies. This led to his hypothesis of sex-limited, also known as sex-linked. However, upon further experimentations, the next generations of crossing the original male with some first generation red-eyed females resulted with both red-eyed and white-eyed males and females, therefore the trait was concluded to be sex-related and the trait of the coloured-eyed gene was found to be on the X-chromosome. Thus the discovery of how genes are transmitted through chromosomes. In 1933, Thomas Morgan

The main purpose of this lab was to utilize the infamous Hardy-Weinberg equilibrium equation to predict the evolutionary modifications a certain species (Drosophila melanogaster) displayed throughout different generations. For this experiment to be carried out, Drosophila melanogaster, also known as fruit flies, were used to visually represent evolutionary conceptions such as Hardy-Weinberg equilibrium equation. At the beginning of the experiment, the parent generation was observed first. Throughout the course of seven weeks, the vial was analyzed for certain changes between the two populations of Drosophila melanogaster; wild type and ebony. Although the genotypes could not be figured out, the flies were evaluated and observed based on

Genes can either be sex-linked or autosomal. If a gene appears mostly in one sex chances are the gene is sex-linked and if it appears frequently in both sexes it is most likely autosomal. Using Drosophila melanogaster, also known as the fruit fly, we will determine whether the gene is sex-linked or autosomal. Drosophila melanogasters have a relatively short life span and are an excellent organism for genetic studies because it has simple food requirements, occupies little space, is hardy, completes its life cycle in about 12 days at room temperature, produces large numbers of offspring, can be immobilized readily for examination and

Introduction Gregor Mendel, the father of genetics, established the basic principles of heredity by crossing different varieties of pea plants and observing the succession of traits in the resulting generations. In order to studying the trends of heredity, model organisms are crossed and observed for the resulting traits. Drosophilia melanogaster, the fruit fly, has been a useful species in the study and practice of genetics. The fruit fly is an excellent model organism due to its short generation time, large offspring numbers, simply and cheap care, easy handling in a lab setting, and large and varied stocks available with minimum cost. It was among the first organisms to be used for genetic analysis (Pierce, 2005).

Abstract Drosophila melanogaster have been tested on by scientists for over a hundred years. Research on these flies have come to be the foundation of genetic studies everywhere (“Drosophila melanogaster”). In this experiment two environments were created where wild type and vestigial Drosophila melanogaster reproduced over multiple generations. One environment has a simulated predator and the other does not.

The Unknown Drosophila Cross Abstract: Genetics is the study of genes, heredity, and variation in living organisms.. Heredity is the passing of traits to offspring from its parents (Bechtel). This is the process by which an offspring cell or organism acquires or becomes predisposed to the characteristics of its parent cell or organism. These characteristics are in a physical sense are known as phenotypes and genotypes in the genetic sense. In the lab, we studied Mendelian Genetics through a common insect of a fruit fly, formally known as Drosophila Melangaster.

When one thinks of Drosophila melanogaster, one should think of Thomas Hunt Morgan, a Noble Prize winner for discoveries regarding the chromosome and a recipient of the Darwin Medal. Morgan was born in Lexington, Kentucky on September 25th, 1866 and was the eldest son of his family. He attended the University of Kentucky, attaining a B.S. degree in 1886, and continued onto John Hopkins University where he studied morphology, a branch of biology dealing with the structure of plants animals (University of Sheffield 2012), and physiology, or the study of how living organisms function (Merriam-Webster). Growing up, he always collected fossils, and just following his graduation from the University of Kentucky, he engaged with laboratory research involving marine life. Following his graduation from John

After completing the experiment, it was evident that the wild allele would result in higher chances in survival and reproduction. When comparing the genders, females were more likely to be in larger numbers. The data was analyzed using the chi-squared value that was calculated for each week. It was determined that on week 3 that it did follow Hardy- Weinberg equilibrium; however, by week five and seven it did not. This proves that our hypothesis was right and the Drosophila melanogaster population did undergo evolution.

His most important contribution to science was to change the view on natural selection. Before his discovery the common view on natural selection was that is produced something close to the best of all possible worlds and that changes would be rare and slow and not apparent over one life span. He observed wild populations of the vinegar fly Drosophila pseudoobscura. While doing this he found extensive genetic variability. In about 1940 evidence accumulated that in a given local population some genes would regularly change in frequency with the seasons of the

80 years ago this animal was able to provide a definite proof that genes are carried on chromosomes. By editing the DNA of this animal, scientists noticed that certain areas of the fly grew differently (a leg on its head) causing mutant flies. With this information, they were able to understand better the cause and effect from the genetic instructions encoded within the chromosomal DNA to the structure of the adult multicellular

3. Carlson, Elof Axel. Mendel's Legacy: The Origin of Classical Genetics. Cold Spring Harbor, NY: Cold Spring Harbor Laboratory, 2004. Print

Another man who contributed greatly to the study of genetics, was an American biologist by the name of Thomas Hunt Morgan. He studied the ways that characteristics were passed from one generation of fruit flies to the next. He learned that the genes in fruit flies behaved in the same way as the genes in pea plants. He also noticed that certain genes were inherited together more often than random chance should allow.