| GENETICS PROBLEMS - Human Blood Types | |||||||||||||||
| BIOL 1406 | |||||||||||||||
| In humans, the ABO blood group is inherited by a single gene (I) with three alleles. The alleles are Ia, Ib, and i. These alleles produce the blood groups A, B, AB, and O. | |||||||||||||||
| The Rh factor of blood is inherited by a separate gene with two alleles. The dominant allele (D) produces Rh positive blood and the recessive allele (d) produces Rh negative blood. | |||||||||||||||
| 1. Bob has type A blood and his mother had type O blood. What is the genotype of Bob and his mother? | |||||||||||||||
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Bob = Iai Bob's Mother = ii
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| 2. If Bob (same as in #1) marries Mary who has type O blood, what blood types are possible for their children? | |||||||||||||||
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Bob = Iai Mary = ii
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3. If Bob ( from #1) had married Greta who has type AB blood, what blood types would have been possible in their children? | |||||||||||||||
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Bob = Iai Greta = IaIb A, AB, and B possible in children
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4. Paula has type B negative blood. Her mother has type O positive blood and her father has type AB positive blood. What is the genotype of each individual? | |||||||||||||||
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Paula = Ibi dd Paula's Mother = ii Dd Paula's Father = IaIb Dd
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| 5. Dick has type AB negative blood and he marries Jane who has type B positive blood. Jane's father has type O negative blood. What blood types are possible in their children and the percent chance of each occurring? | |||||||||||||||
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Dick = IaIb dd Jane = Ibi Dd
AB positive = 1 = 12.5% B positive = 2 = 25% AB negative = 1 = 12.5% B negative = 2 = 25% A positive = 1 = 12.5% A negative = 1 = 12.5%
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| 6. A woman with type A positive blood is married to a man with type B positive blood. If they have a child with type O negative blood, what is the genotype of each individual? | |||||||||||||||
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Woman = Iai Dd Man = Ibi Dd Child = ii dd
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| 7. Sarah has type A positive blood and one of her parents had type O negative. She marries Bill who has type B negative blood. One of Bill's parents had type O positive blood. What are the blood types possible in their children and the percent chance of each occurring? | |||||||||||||||
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Sarah = Iai Dd Sarah's Parent = iidd Bill = Ibi dd Bill's Parent = ii D_
AB positive = 1 = 12.5% A positive = 1 = 12.5% AB negative = 1 = 12.5% A negative = 1 = 12.5% B positive = 1 = 12.5 B negative = 1 = 12.5% O positive = 1 = 12.5% O negative = 1 = 12.5%
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| 8. A woman with type B positive blood gives birth to a baby with type O negative blood. She claims the father is a man with type A negative blood. Based on the blood type information, could he be the father? Why or why not? | |||||||||||||||
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Woman = Ibi D_ Man = Ia_dd Baby = iidd
Yes he could be the father. If woman is heterozygous for type B and Rh positive and the man is heterozygous (Iai) for type B blood. They can produce a child with type O negative blood.
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| 9. A woman with type A negative blood gives birth to a baby with type AB positive blood. Could the father be a man with type O negative blood? | |||||||||||||||
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Woman = Ia_ dd Father = ii dd Baby = IaIb Dd
No he could not be the father. The father has to be someone who can contribute the Ib gene for the baby's blood to be AB.
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| 10. Parents with blood types B positive and A negative bring home a baby that has type O positive blood. They are convinced that the baby was switched at the hospital. Based on the blood type information of the three individuals, could this baby be theirs? How could it be conclusively proven that this is their child? |
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Father = Ib_ D_ Mother = Ia_ dd Baby = ii Dd
Yes this baby could be theirs, if the parents are both heterozygous (Ibi and Iai) for the ABO gene. Can be proven using DNA testing. |