Genetic problems 1. Pure-breeding affable flies are crossed to pure-breeding striped flies. The F1 flies are all striped. (Both of these genes are autosomal and linked.) Which trait(s) are dominant? The F1 females are test-crossed with the following results: affable 99 striped 101 affable striped 102 wildtype 98 What is the linkage arrangement of the F1 flies (coupling or repulsion)? What is the phenotype of the test cross males? What is the map distance between these genes? What would be the ratio if the F1 males were test-crossed? 2. Diagram the expected progeny in the following cross, where M represents an unknown dominant mutant: Genotype Cy M+ ; D males X Cy+ M+ ; D+ females Cy+ M D+ Cy+ M+ D+ Phenotype? What would be the outcome if the above males were crossed to females homozygous for M? 3. m is a recessive unknown autosomal mutant. F1 males of the phenotype curley and dichaete (from a cross of Cy/Pm; D/Sb X m/m) are backcrossed to m/m females. The progeny phenotypes are listed below. On which chromosome is m located? Progeny Curly Dichaete Curly "m" dichaete "m" 4. m is a recessive unknown autosomal mutant. F1 males of the phenotype Cy D (from a cross of Cy/Pm; D/Sb X m/m) are backcrossed to m/m females. The progeny phenotypes are listed below. What chromosome is m located on? Progeny Curly Dichaete "m" Curly Dichaete Curly "m" Curly Dichaete "m" Dichaete "m" wild type
