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Blood Type Activity:  Exploring the relationship among three alleles.

GenScope File:

When this file is opened, a pedigree of three families appears. There are four blood types, A, B, AB, and O. A and B are incompletely dominant to each other and both are dominant to O.

1.       Trish is Type B and her son, Len, is type AB.   What is Ron's blood type?

How do you know?


2.       Is it possible for Janis and John to have a child who is type O?

How can you explain this?
3.       Is it possible for Stacie and Harry to have a child who is type O?

4.       Len and Claire and Melanie and Bob were in the same hospital at the same time when they had their respective babies. Len and Claire had twins, a boy, James, and a girl, Jill. Melanie and Bob had a boy, Howie. After being home for a few days, Claire was convinced that she had the wrong boy. There must have been a mix-up at the hospital. After all, her kids were twins, and even though they were fraternal twins, you would think that they would look a lot more alike than they do - one is blond and the other is brown haired. At their insistence, blood types were taken on both their family and Melanie and Bob and their son. The results were as follows:

Claire is type B
Len is type AB

Melanie is type B
Bob is type A

James is type B
Jill is type A
Howie is type O

Was a switch made at the hospital?

How do you know?

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