Drosophila Melanogaster : A Great Species For Students Study The Process Of Mendelian Inheritance

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.

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.

The motivation of this lab report is to use Mendel’s Laws of Inheritance to analyze and predict the genotypes and phenotypes of an offspring generation (F2) after knowing the genotypes and phenotypes of the parent generation (F1). The hypothesis for this experiment is that the mode of inheritance for the shaven bristle allele in flies is autosomal recessive in both male and female flies.

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’

Mendel’s law of independent assortment deals with dihybrid crosses meaning that independent assortment dealt with the crosses in Group 2 (ap+/ap; se+/se x ap+/ap; se+/se) and Group 4 (vg+/vg; se+/se x vg+/vg; se+/se). This is also the law of independent assortment as the cross deals with the production of haploid cells to the offspring (Gen.: Analysis & Principles, p28). Independent assortment is observed in these two crosses as there are to different traits within the

Mendel’s first law of inheritance is also known as the law of equal segregation. This law states that the two members of a gene pair segregate equally into gamete cells. In other words, each sex cell contains only one copy of a gene. Mendel discovered the second law—now known as the law of independent assortment—while studying dihybrid crosses. This law states that genes assort independently during gamete formation. This explains how there are different combinations of different phenotypes. In peas, for example, yellow color is not always associated with a round shape. There can be different combinations of round and wrinkled shape with yellow and green color (Griffiths, 2015). Though there are some exceptions to this rule, such as linked genes and sex-linked genes, the traits investigated in this experiment strictly follow Mendelian inheritance.

The Drosophila melanogaster is one of genetics most studied organisms. This is due to the Drosophila melanogaster being an excellent model organism. The Drosophila melanogaster has a short lifespan and is genetically similar to humans (Adams 2000). This experiment had three major goals. The first goal of this experiment was to determine which eye colors, body colors and wing type are dominant or recessive. The second goal was to determine if the gene for eye colors, body colors and wing type are on an autosomal or a sex chromosome. The third goal was to determine if eye colors, body colors and wing type are physically linked or independently assorting (Morris and Cahoon). First

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

The progeny of this cross were known at the F1 generation. Phenotypes seen in this cross were recorded. Males from this cross were collected. A male that with a different phenotype from the mutation in the mutant flies was selected. (If the mutation in the mutant flies is white-eye, a male without an eye mutation is selected.) The selected male from the F1 generation is then crossed with a virgin female from the parental generation. After which, the phenotypes seen were recorded and used to determine which chromosome the mutation is located on and what the mutation is.

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.

Genetic crosses: Genetic crosses show how characteristics are inherited through the generations. In a monohybrid cross each parent contributes two alleles, producing four possible combinations for the one trait. A dihybrid cross involves two alleles per trait for two traits, for a total of four alleles. Each allele of a particular trait has an equal chance of being in a gamete with each of the alleles of the other trait.

When asked about mutations, common answers could be “it could be genetic” or “something probably went wrong during the gestational period” but do people really know the underlying truth about mutations? For example, not much is known about the white eyed phenotype in Drosophila melanogaster. Understanding how the white eyed phenotype is inherited in these flies could allow other scientists/researchers to be closer in solving genetical problems in humans. This study attempts to understand how the white eyed phenotype is inherited and which its mode of inheritance might be; whether it’s sex-linked (dominant or recessive), autosomal (dominant or recessive), incomplete or complete dominance.

These phenotypic markers make it easier to determine how the insertions and mutations and were being separated from one generation to another. In this experiment F2 progeny flies with white eyes had to be scored for both the crosses mentioned

The main purpose for this conducting this experiment was to further knowledge on Mendelian Genetics and how traits are inherited from generation to generation. Something that we attempted to solve was which traits were considered dominant and which were considered to be recessive. Drosophila melanogaster also known as fruit flies were used in this experiment, Dihybrid crosses were done to gather information on how characteristics are linked from generation to generation. Our crosses consisted of female wild type with male sepia eye/ ebony body and female ebony with male vestigial. It is shown that some inheritance patterns are due to unlinked genes and linked genes.

Morgan’s studies of sex-linked traits in fruit flies led him to suggest that the genes