Punnett Squares

The scenario:  Disaster!  Terry and Kim go to a hospital… a bad hospital… the kind you see on “The Learning Channel” where babies are routinely switched at birth.  There are TWO babies that might be theirs!  The babies’ names are Sven and Ollie.  Sven has blood type B, while Ollie has blood type O.  Both Terry and Kim have blood type A.  Which baby, if either, is theirs?

Draw punnett squares to illustrate ALL OF the potential patterns of heredity and solve this mystery!  Don’t worry about + or -, this refers to the presence or absence of a protein called Rh Factor on the surface of your red blood cells.… While important if you are donating blood, it is irrelevant to this exercise.  Could either baby belong to Terry and Kim?  

If you don’t remember how to draw punnett squares, check out this video <https://www.youtube.com/watch?v=prkHKjfUmMs>.

Remember, blood types can be either homozygous dominant, homozygous recessive, or heterozygous.  Thus, somebody with A blood could be either IAIA(homozygous dominant) or IAi (heterozygous), somebody with B blood could be either IBIB (homozygous dominant) or IBi (heterozygous), somebody with AB blood is IAIB (heterozygous), and somebody with O blood is ii (homozygous recessive).

IMPORTANT!  SAVE YOUR PUNNETT SQUARES AS A .JPEG AND ATTACH THEM (draw it in Illustrator, on piece of graph paper). 

*Make sure you indicate which, if either, baby could belong to Terry and Kim.

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