Blood Typing Problems and The Case of the Long Lost Son

Part 1

  1. What blood type would a person with the genotype IAIB have? ______
  1. What blood type would a person with the genotype IAi have? ______
  1. What blood type would a person with the genotype IBIB have? ______
  1. What blood type would a person with the genotype ii have? ______
  1. What blood type would a person with the genotype IBi have? ______
  1. A man with type AB blood is married to a woman also with type AB blood. What blood types will their children have? What is the phenotypic ratio?
  1. A man has type B blood (genotype IBIB) is married to a woman with type O blood. What blood types will their children have? What will be the genotypes of the children?
  1. A woman with type A blood (genotype IAi) is married to a type B person (genotype IBi). What proportion of their children will have: A blood? B blood? O blood?
  1. A woman with type A blood is claiming that a man with type AB blood is the father of her child who is also type AB. Could this man be the father of the child? Show the possible crosses; remember that the woman can have AA or AO genotypes.
  1. A woman with type O blood is claiming that a man with type AB blood is the father of her child who is type O. Could this man be the father of the child? Show the cross.
  1. A man with type AB blood is married to a woman with type O blood. They have two natural children and one adopted child. Jane has type A blood, Bobby has type B blood, and Grace has type O blood. Which child was adopted? (Use a Punnett Square and show all work)

Part 2: The Long Lost Son:

Mr. Howell died and left all his money to his two children. A young man claiming to be a lost third child sued for his share of the estate. The judge ordered blood tests for all family members and for the young man.

Mr. Howell’s blood type was already on record. He had type AB blood. His wife had type A, and theyoung man who claimed to be the long lost son had type O blood. The judge quickly dismissed the case.

  1. What are the possible genotypes of the young man claiming to be Mr. Howell’s long lost son?

______

  1. Create a Punnett square and find the offspring that can be produced if Mrs. Howell had the genotype IAIA and Mr. Howell had the genotype IAIB.
  1. What are the possible phenotypes of the offspring? ______
  1. Does this outcome support or refute the judge’s decision? ______
  1. Create a Punnett square and find the offspring that can be produced if Mrs. Howell had the genotype IAi and Mr. Howell had the genotype IAIB.
  1. What are the possible phenotypes of the offspring? ______
  1. Does this outcome support or refute the judge’s decision? ______
  1. Based on the Punnett squares you created, list all the possible blood types that Mr. Howell’s offspring could have:
  1. Do you agree or disagree with the judge’s decision? Explain your answer in at least 2 sentences.

Part 3: Sex-linked Traits

Use the information below to answer the following questions.

XH- X chromosome with normal dominant allele (no hemophilia)

Xh - X chromosome with recessive hemophilia allele

Y - Y chromosome (does not contain comparable gene)

XB - X chromosome with normal dominant allele (not colorblind)

Xb - X chromosome with recessive colorblind allele

Y -Y chromosome (does not contain comparable gene)

  1. A normal-sighted woman (whose father was colorblind)

marries a colorblind man. ______X ______

a. What is the probability that they will have a son

who is colorblind? ______

b. What is the probability that they will have a

colorblind daughter? ______

2. What is the probability that a colorblind woman who marries a man with normal

vision will have a colorblind child? ______

______X ______

Multiple Choice Practice

  1. A human female carrier who is heterozygous for the recessive, sex-linked trait causing red-green color blindness marries a normal male. What proportion of their male offspring will have red-green color blindness? Complete a Punnett square to help you show the evidence.
  1. 100%
  2. 75%
  3. 50%
  4. 25%
  5. 0%
  1. A female Drosophila of unknown genotype was crossed with a white-eyed male fly, of genotype XrY (r = white eye allele is recessive, R = red-eye allele is dominant.) half of the male and half of the female offspring were red-eyed, and half of the male and half of the female offspring were white-eyed. What was the genotype of the female mother fly?
  1. XRY
  2. XRXR
  3. XrXr
  4. XrY
  5. XRXr
  1. Women have sex chromosomes of XX, and men have sex chromosomes of XY. Which of a woman’s grandparents could not be the source of any of the genes on either of her X chromosomes?
  1. Mother’s father
  2. Father’s mother
  3. Mother’s mother
  4. Father’s father
  5. Mother’s mother and mother’s father

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