Expert: Walter Hintz - 3/6/2010

Question
I was wondering how you got those gametes because I also must answer the questions of the Purple People Eaters question for my biology class. Our teacher taught us to FOIL for the dihybrid crosses but I dont know how to get the gametes for trihybrid crosses. It would be great if you could help me.

Answer
Hi Gigio
I am not sure what you mean by FOIL but the important thing is to separate the alleles. For example let is say  that the three traits are
AA  BB   and CC
So the genotype would be AABBCC and the gametes would be ABC.
Now lets make two  of the traits heterozygous
 AaBbCC and gametes from this individual would  be
  ABC
  AbC
  aBC
  abC

assume a genotype AaBbCc  You show the gametes and let me know