The law of independent assortment states that each pair of alleles segregates independently during gamete formation. Together, all five concepts make up the Mendelian model that is soon to be demonstrated. In a typical breeding experiment, Mendel mated two contrasting, true breeding varieties. The true breeding parents are the P Generation. The hybrid offspring of the P Generation is called the F1 Generation, and when F1 individuals cross breed, the F2 Generation is produced. Through the experimental approach, observations led to conclusions that allowed Mendel to develop a model that explained a consistent ratio that he constantly observed among the f2 offspring. When breeding two true breeding pea varieties with two different characters, such as a plant with yellow round seed and a plant with green wrinkled seeds, the F2 Generation exhibited a 9:3:3:1 phenotypic ratio. While Mendel's research was with plants, many traits of humans and animals follow Mendel's patterns of inheritance. Knowing that, mendel's model can be used to study patterns of inheritance in fruit flies. The common fruit fly, Drosophila melanogaster, is a very convenient organism for genetic studies because it is a very prolific breeder, easily cultured in lab, and has a relatively short generation time of 10 to 14 days (lab manual, and textbook). In fruit fly genetics, a normal fly is called a "wild type" and has red eyes, a grey body color and normal wings. A mutant fly has white (w) or sepia eyes (se), a black (ebony) body color (e), and no wings (ap) or very small wings (vg). A superscript + identifies the allele for the wild-type trait. For example, an e+ allele symbolizes the normal (wild) color, grey, of a fruit fly. A mutant (variant) allele for body color is symbolized by e. .
Purpose.
The purpose of this lab is to use the characters of body color and wing shape in fruit flies to follow traits through two generations.