Drosophila Inheritance Patterns

Drosophila Inheritance Patterns
Gage Howard
May 7, 2012
Honors Genetics
Mrs. Jennings

ABSTRACT

INTRODUCTION The purpose of this experiment was to determine the inherited patterns of the eye color and the types of wings of all of the fruit flies, Drosophila melanogaster. The wild type phenotype eye color is red, and the mutant eye color is sepia, a brownish- black color. The wild type phenotype wing shape is elongated, and the mutant wing shape is shorter and crinkled. The Drosophila melanogaster has four chromosomes. The gene that has a mutant inheritance it is found on chromosome two and three. There are four distinct stages in the life of the fruit fly: egg (Fig. 1), larva (Fig. 2), pupa (Fig. 3), and adult (Fig. 4). At room temperature, a fresh culture of the Drosophila melanogaster will produce new flies in two week: eight days in the egg and larva stages, and six days in the pupal stage. Two days after the flies emerge the female flies are already starting to reproduce. The Drosophila melanogaster is a good type of fruit fly for genetic studies because they are easily cultured, the flies have a great generation time, and D. melanogaster also have good mutant forms. A female can lay six hundred eggs in just ten days (Flagg, 2005). It is hypothesized that the mutant phenotypes of vestigial wings and sepia eye color are inherited in an autosomal recessive fashion as evidence by the F2 generation showing a Mendelian inheritance pattern of a 9:3:3:1 phenotypic ratio supported by a chi-square test. The Mendelian inheritance is a scientific theory of how hereditary characteristics are passed from parent to organisms to offspring. This theory was originally derived from Gregor Mendel. Gegor studied pea plants and said that in the genetic inheritance patterns, there was a dominant and recessive gene, and that the dominant gene is more expressed over the