[ThinkDifferent]

If both parents have the non-dominant redhead gene, it can become dominant in their offspring. A 25% or 50% chance.

If both parents carry a single recessive gene, then each child has a 25% chance of getting two recessive genes, and a 50% chance of one dominant and one recessive.

[BobS]

And a 25% chance of getting 2 dominant genes. Now I remember after 35 years. I just drew the relationship out too! 2^2=4 way action. John Thune better explain dating to his red head girls soon. He could have problems:)