7.7 Genes a and b are 20 cM apart. An at b*la* b* individual was mated with an a bla b individual. (a) Diagram the cross and show the gametes produced by each parent and the genotype of the F₁. (b) What gametes can the F₁ produce, and in what proportions? (c) If the F, was crossed to a bla b individuals, what off- spring would be expected, and in what proportions? (d) Is this an example of the coupling or repulsion link- age phase? (e) If the F, were intercrossed, what offspring would be expected, and in what proportions?

Part 1: Make a three part process drawing (like a cartoon strip) to demonstrate Mendel's Principle of Segregation. Use two parents with homologous chromosomes marked with alleles "A" and "a". Circle and label these three action parts of the Principle of Segregation: a) parents are diploid, b) alleles separate to form haploid gametes (indicate when this happens), and c) gametes from each parent combine at random to form diploid offspring Part 2: Use the cross Aa x Aa and a Punnett square to demonstrate Mendel's Principle of Segregation. Circle and label these three action parts of the Principle of Segregation: a) parents are diploid, b) alleles separate to form haploid gametes and c) gametes from each parent combine at random to form diploid offspring. Part 3: Use homologous chromosomes marked with alleles "A" and "a" and a second pair of homologs marked with alleles "B" and "b". to demonstrate Mendel's Principle of Independent Assortment in cells in Meiosis. Indicate what phase this…

4:12 5. Set up the punnett square for each of the crosses listed below. The characteristic being studied is seed texture round seeds (dominant) and wrinkled seeds (recessive). Rr x rr Rr x Rr RR x Rr Tall: % Complete the punnett squares below using the given information. 6. A TT (tall) plant is crossed with a tt (short plant). Which trait is dominant? Give the expected probabilities for each genotype and phenotype. TT: Tt: Short: Previous % % tt: What percentage of the offspring would you expect be round? Wrinkled? ZOOM + What percentage of the offspring would you expect be round?_____ Wrinkled? What percentage of the offspring would you expect be round? Wrinkled? % 7. A hybrid tall (Tt) plant is crossed with a hybrid (Tt) plant. Give the expected probabilities for each genotype. phenotype. wvm.instructure.com

In D. melanogaster, reduced bristles (rd), cinnabar eyes (cn), and vestigial wings (vg) are recessive traits located on chromosome II in that order. The distance between rd and cn is 7 cM and the distance between cn and vg is 9 cM. The CoC for this chromosome is 0.9. A true-breeding female expressing cinnabar eyes and vestigial wings is crossed to a true-breeding male expressing reduced bristles. The F1 are wild type. An F1 female is then test crossed to a male expressing all three traits. Among the F2 progeny, how often would you expect to observe flies expressing only cinnabar eyes? Using the same information from above, among the F2 progeny, how often would you expect to observe flies expressing only vestigial wings?