Tracing The Genetics Of A Fruit Fly

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. Mendel’s experiment was to cross pollinate pea plants and observe how traits were passed on. He started his experiment with two true breeding pods,

The parents are both homozygous. The homozygous dominant would represent the wild type. And the homozygous recessive would represent the other fly parent of a different strain. The F1 generation would consist of 100% Wild Type but they would all be heterozygous in carrying the recessive gene.

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.

It would be expected that the mutant F1 flies would be heterozygous for the allele responsible for the grounded trait. If two F1 flies were mated, the percentage of flies that would be expected to be wildtype in the F2 generation would be 25% mutants given that the mutant allele (ap) is predicted to be recessive and, leaving 75% to be wildtype (ap+).

Purpose The purpose of this experiment is to determine whether the fruit flies were dominant/recessive or linked/non-linked. The traits I chose for this activity was the fruit fly with vestigial wings and purple eyes, the other fruit fly I chose was a normal fly, also called wild type. While writing out my plan for this activity I thought it would be interesting to test a female mutant and the wild type male, the ratios I came up for this experiment was 2:2 and the mutant allele being recessive to the wild type. In this case, the words recessive and dominant means, if the child born from the parents inherits more of the genes and traits from let us say the father then the alleles of the father is dominant over the mother’s genes.

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.

Gregor Johann Mendel, the father of genetics, was born in 1822. He was a priest and scientist who became famous for his work and studies on the inheritance patterns using pea plants. Gregor Mendel used pea plants known as Pisumsativum in his research where he developed two fundamental laws of genetics known today as the “Law of segregation”, and the “Law of independent assortment” (Hartl, 1992). The “Law of segregation” states that when an individual produces a gamete, the copies of a given gene separate in which each gamete receives only one copy of that gene. The phenotypic ratio in the F2 generation according to the “Law of

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’

The fruit fly, Drosophila melanogaster, became an important model organism for the study of human genetics and for the establishment of more biological principles (Roberts 2006). This organism became a good candidate to work with because of its short life cycle, its inexpensiveness, small size, its genetic variability, easily cultured and its ability to produce many offspring. Nichols and Phandey made an important discovery: approximately 75% of disease-causing genes in humans are homologous to genes found in Drosophila melanogaster (Russell and Tickoo). This is an important observation, because it made it possible to discover treatments for human diseases. For example, the fly has a tumor gene homologous to the human LATS1 gene.

Genetics shows us that we inherit traits in many different ways. A perfect example to show us the different ways we inherit traits is fruit flies. Fruit flies are commonly used by scientists to conduct genetic experiments due to their reaction to the experiment being very quick. Scientists mainly look at how the flies inherit basic traits such as brown body color, or red eyes(basic trait flies are known as wild-type flies) from their parents, but sometimes they can come across some abnormal traits. Some of these abnormal traits include having a yellow body color or having curly shaped wings and have made scientists wonder how the flies have inherited these specific traits. So how do the flies inherit

“The cellular machinery that copies DNA sometimes makes mistakes,” there are about 37.5 trillion cells in the human body, and their job is to make copies of DNA, yet sometimes the cells make a mistake and either switch, remove, or add a gene. This does not occur often, so when it does these mistakes are called mutations. Another reason that signifies why mutations are unusual is because mutations are mostly recessive traits. In an online article, Fruit Fly Phenotypes it informs us about fruit flies and some of the mutations, “This mutation is a recessive trait, meaning that the fly won't express the gene unless it gets it from both parents.” In other words some mutations are recessive traits meaning both parents must have the trait for the offspring to have the mutation as well. According to a lab, Genetic Variation in Monsters, “Recessive traits only show up if dominant traits are absent and are represented by a lowercase letter. Dominant traits show up in the offspring whenever present.” This is an explanation of what recessive and dominant traits are, in quotes it says that dominant trait are found anywhere where at least

Introduction Have you ever wondered how specific traits are passed down from generation to generation? Or if you already know the answer to that question, then how can you determine which traits are dominant and recessive. Finding both answers can be obtained by studying genetics. Reading about these topics only gives you a grasp on how traits work. In a laboratory setting, the answers can be found in an experiment using an unlikely specimen, known as the common fruit fly and its scientific name, Drosophila Melanogaster.

In this experiment we bred drosophila with unknown genotypes, which are the actual genes of an organism, to see what the phenotype of their offspring would be. Introduction: T. H. Morgan was a geneticist who worked in the early part of the twentieth century. He was the first to use fruit fly, Drosophila melanogaster, as a model organism in genetic studies. He developed a name for himself that way and the science world wouldn’t be the same with out his discovery.

The Drosophila melanogaster, commonly referred to as a fruit fly is used as a model organism to study genetics, evolution, or allele frequencies. They are easy to obtain and their generation time span is very short being only ten days, making it the best option to observe changes in a population in a timely manner (Johnston, 2002). In a study done by Johnson, they used drosophila melanogaster to observe a genetic drift occur to the population’s frequencies when put into different suitable habitats. They used the Hardy-Weinberg equation to calculate it and the results were mostly what they had expected. Many of the flies developed different types of eyes and wings (Johnson, 2009).

Abstract The objective of this lab to, develop an understanding of the inheritance patterns observed in a fruit fly. For this experiment we used Drosophila melanogaster as a model organism due to its short life cycle, small size, and its virtual inexpensiveness. Drosophila melanogaster commonly known as the fruit fly used in this experiment provided experimental data that was in agreement with the laws of segregation and independent assortment proposed by Gregor Mendel.