determine from the outcome of genetic crosses whether a set of mutations that cause the same phenotype are located in the same gene or different genes. 1. Three mutants with the same disease phenotype were isolated. When crossed, mutants 1 and 2 showed "complementation" and mutations 1 and 3 showed "non-complementation". A) Fill in the pedigrees below to reflect this information, using capital and small letters to represent different possible alleles. For these pedigrees, imagine there are two possible genes that could be involved (A/a and B/b). # 1 X #2 Complementation # 1 X #3 Non-Complementation B) If the female and male from generation 2 of the two pedigrees above were to have offspring, what percent of their offspring would show the mutant phenotype? 2. You are studying the genetics of eye formation in fruit fly. Five different mutant strains of flies have been isolated (A-E) and each shows a recessive 'eye-absent' trait (i.e. very small or no eye). Crosses were performed with flies from each strain to test whether they result in a mutant (eye-absent) or wild type (normal eyes) phenotype. A. If the cross results in a mutant phenotype, do these mutations complement or fail to complement? B. If the offspring of the crosses are mutant, they are represented as "-" in the table below, while if the offspring are normal, they are represented as "+". A B C E A B D + I - ? + D E From this information, which flies have a mutation in the same gene (are in the same complementation group)? C. Based on the information in the table, at least how many genes can result in a no-eye fly when mutated? +