In dihybrid crosses of heterozygous parents, the ratio 9:3:3:1 indicates ___. a. codominance                                  c. incomplete dominance b. independent assortment                 d. three alleles for each trait For the next four questions, use the following key: a = All the offspring will exhibit the dominant trait.       c = The recessive trait will show up in about 50% of the offspring. b = All the offspring will exhibit the recessive trait.       d = The dominant trait will show up in about 75% of the offspring. What will be the result if: 9. Bb mates with bb?              10. BB mates with bb?

1,Show the cross between two people with Type AB blood. What is the genotypic and phenotypic outcome of such a cross?   2. Incomplete dominance = If a Red (RR) and White flower (rr) were crossbred, resulting in 100% Rr, what phenotype(s) would been seen according to the rules of IN-complete dominance?   3. Two parents think their baby was switched at the hospital. Its 1968, so DNA fingerprinting technology does not exist yet. The mother has blood type “O,” the father has blood type “AB,” and the baby has blood type “B.”   Mother’s genotype: _______ Father’s genotype: _______ Baby’s genotype: ______ or _______ Was the baby switched? ____________________________________________________

6.    A heterozygous purple plant is crossed with a white plant. A.    Write the genotype of the purple and white plants. B.    Write the gametes formed by the purple plant and proportions in which they occur.   C.    Write the gametes formed by the white plant and proportions in which they occur.   D.    Combine the gametes using a Punnett square.           E.    Write the genotypes of the offspring and the ratio in which they occur.     F.    Write the phenotypes of the offspring and the ratio in which they occur.       7.    The ability to roll your tongue (R) is dominant to lack of this ability (r). A.    What is the genotype of a man who can roll his tongue if his father couldn’t? B.    If a man who is heterozygous for tongue rolling marries a woman who is heterozygous, what would you predict for the genotypes and phenotypes of their children?                               8.     Huntington’s disease is a degenerative disease of the nervous system that strikes in middle age. The…