University of Tennessee, Martin

• BIOLOGY 110

• Gene Mapping Worksheet 1. The crossover frequency between genes E and F is 6%, between E and G is 10% and between F and G is 4%. Construct a gene map. Determine the sequence of genes on the chromosome. E (6) F (4) G OR G (4) F (6) E 2. The following chart shows the crossover frequencies for some genes on an autosome of organism Z. Construct a chromosome map. Genes Crossover Frequency P & Q 5% P & R 8% P & S 12% Q & R 13% Q & S 17% Q (5) P (8) R (4) S 3. For a series of experiments, a linkage group composed of genes W, X, Y and Z was found to show the following gene combinations. (All recombinations are expressed per 100 fertilized eggs). Construct a gene map. Genes W X Y Z W – 5 7 8 X 5 – 2 3 Y 7 2 – 1 Z 8 3 1 – W (5) X (2) Y (1) Z 4. In Drosophila, the gene for eye color (A), wing shape (B), and body color (C) are all found on the same chromosome. The following crossover frequencies for these genes were determined by experiments. Genes Crossover F