Name : ______
More Genetics Problems, Yippee!
Blood-Type Problems. Remember that A and B are codominant and that o is recessive!
1. If a man with blood type AB marries a woman heterozygous for type A, what is the probability that their child will be type B?
2. A mother has type A blood and a father has type B blood. If their baby has type O blood, what is the genotype of the parents?
3. Use a punnett square to show the possible genotypes and phenotypes for blood type of the offspring of two parents, one with blood type O and one with blood type AB.
4. Two women gave birth to girls in the same hospital at the same time. The nurses think they may have accidentally switched the babies' name tags and given the babies to the wrong parents. One baby, Jane, is type O. The other baby, Mary, is blood type A. The father in one set of parents, the Reds, is blood type A, and the mother is type B. The father in the other set of parents, the Greens, is blood type AB, and the mother is type O. Figure out which baby belongs to which parents. Show your work and reasoning.
Sex-Linked Problems. Remember to show females as XX and males as XY!
2. Color blindness is a sex-linked recessive trait. What is the probability that a color blind woman and a color-blind man will have: a. a normal sighted son b. a color blind daughter
2. What is the probability that two parents with normal color vision will have color blind sons or daughters if the mother's father is color -blind?
4. Hemophilia is a sex-lined blood disorder. People with this disease can bleed to death from a small cut because their blood does not clot. It is caused by a recessive allele. You are a normal (homozygous) female who is about to marry a hemophiliac male. What are your chances of having a child with this blood disorder?
4. In Drosophila, the gene for red eye color, “R”, is dominant to the gene for white eye color, “r”. The trait is sex-linked. A red-eyed male was bred to a heterozygous red-eyed female. Mark true/false.
______The genes for eye color are carried on the X chromosome.
______The male's genotype is XRYr.
______The female's genotype is XRXr.
______Half of the gametes produced by the female should contain Xr.
______All the gametes produced by the male should contain Yr.
______Of the offspring produced, all females are expected to have red eyes.
______Of the offspring produced, all males are expected to have white eyes.
______The offspring of a white-eyed male must have the genotype XrY.
______Female offspring produced from this cross could have the genotype XrXr.