Crossing Flies to Demonstrate Inheritance Patterns

Introduction: The intention of this lab was to gain a better understanding of Mendelian genetics and inheritance patterns of the drosophila fruit fly. This was tasked through inspecting phenotypes present in the dihybrid crosses performed on the flies. An experimental virtual fly lab assignment was also used to analyze the inheritance patterns. Specifically, the purpose of our drosophila crosses is to establish which phenotypes are dominant/recessive, if the traits are inherited through autosome or sex chromosomes and whether independent assortment or linkage is responsible for the expressed traits.

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 Drosophila melanogaster is a fruit fly with a very short life cycle. They can be winged or wingless, and have red eyes or white eyes. The different options are called alleles. Alleles are the variants of a specific gene, and one is received from each parent on each chromosome. (“What Are Dominant and Recessive?”). It was chosen to use winged females and wingless males to predict the offspring in this experiment. The winged allele is dominant, meaning it only needs one allele to physically appear. The wingless allele is recessive, which gets covered up by the dominant allele (“Fruit Fly Genetics”). Each trait has two alleles in the flies’

There have been numerous studies done on Drosophila melanogaster and one such study was by Kalmus in 1935. This study was concerned with the clock system that controlled the time at which Drosophila adults emerged from puparia (Kalmus 1935). J.M. Rendel also did a study on Drosophila. His focus was the differences in mating behavior that was displayed between most species of Drosophila (Rendel 1951).

Introduction For centuries, researchers have used Drosophila melanogaster, the common fruit fly, to study genetics. The benefits of using the fruit fly includes: its relatively short generation time, its large amount of available offspring for data, it is easy to store and handle in the laboratory and it is easily and cheaply obtained. Cross-breeding of four types of fruit flies were used in this experiment including: wild type males with normal wings vs. vestigial wing females, wild type males with red eyes vs. white eyed females, wild type male with red eyes vs. sepia eyed females, and wild type males vs. wild type females. In basic mendelian genetics, the terms dominant, recessive and sex-linked are used to describe the different types

The reading discusses the use of experiments by scientist to study causation to find out what causes what. The fruit flies are the subjects to conditions, administer the treatments, and measure the outcomes. In the experiment, there is only one important difference between the conditions being linked. Researching the brain and how different receptors sites play a role in developing medication to those with mental illness is important. Finding the link of between chemical deficiency and mental illness can improve a patient outcome.

we said goodbye and placed them in the fly morgue. We allowed the F2 larval

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

Fruit Fly experiment was conducted by using different techniques. One of the main things was to examine the fruit flies and identify the difference between females and males, identify their mutation if they were wild type, white eye, vestigial or white and vestigial combined together. These Fruit flies were kept in the incubator at 25°C for about 6 days. The main goal for this experiment was to observe the principles of Mendelian genetics.

Finally the experiment that Mendel performed has helped the Science world tremendously. He has made it easier for Scientist to work with traits. He has made so that Scientist are able to understand how traits are passed down from parent to child and in some cases from Grandparent to Grandchild if it skips a generation. It also helps Scientist understand the reasons behind traits and why they are the way that they are.

In this experiment we tested to see what the offspring of an unknown cross of an F1 generation would produce. After observing the F2 generation and recording the data we found some of the Drosophila showed mutations, two in particular. The mutations were the apterus wings, and sepia eyes. After collecting our data through observation, a Chi-test was conducted resulting in a Chi-value of 5.1 and a p-value of .2. Since the p-value was greater than 0.05, there was no significant change in the data. This proved that the Drosophila flies still followed the Mendelian genetics of a 9:3:3:1 ratio.

This experiment looks at the relationship between genes, generations of a population and if genes are carried from one generation to another. By studying Drosophila melanogaster, starting with a parent group we crossed a variety of flies and observe the characteristics of the F1 generation. We then concluded that sex-linked genes and autosomal genes could indeed be traced through from the parent generation to the F1 generation.

Everyone stands to benefit from the developments made in the field of genetics as everyone is made of genes. Genetics is the study genes and how they influence human biology. Genes are the molecular unit of inheritance found in cells, these genes encode everything about human physiology ranging from eye/hair colour to height, possible mental/physical disorders and so on. The field of genetic testing is concerned with advancements in the study of the functions of individual genes and how they influence living things. Major advances have been made in the study of the genetic structure of humans and external influences to our internal makeup, such as our quality of life and their implications that may have on our physical and mental development.

One icon of evolution is said to be the four-winged fruit fly. The fly is supposed to show the process of evolution by how mutations can affect the process of development. There is a slight problem with it though, its extra two wings are not connected to muscle, which makes them pretty much dead. The fly can only survive in the laboratory because it is selected out by natural selection. Other flies do not want to reproduce with it, so unless controlled by humans, they cannot reproduce.

There has been a lot of scientific research done into genetics, genetic crosses and inheritance enabling us to understand why we have the certain characteristics and traits that we do, how we inherited them and how we can pass them on. It’s because of this research that we can understand and learn about our genetic makeup and why it effects the way we are.