If person 12 married a colorblind man, what are the possible genotypes and phenotypes if they had a child? 30 points!

REMEMBER: color blindness is carried on the X chromosome only! The male has to inherit the mutated gene from his mom and her X chromosome to be color blind. Because the male has only 1 X, he has a greater chance to be color blind than a daughter who would have to inherit a bad X chromosome from each parent!

If you follow the family tree, the person 12 (the daughter of 4x5) could be either XX or XX (I'm using bold to indicate the color blind gene on the X chromosome). You cannot tell from this family tree what she is (except that we know her mom (4) is definitely a carrier!

So you need to do two potential crosses:
1. Daughter 12 is not a carrier; so she is XX
Cross XX with XY; you get the possibility of all daughters as carriers XX, or all normal sons XY.

2. Daughter 12 is a carrier; so she is XX
Cross XX with XY; you get the possibility of daughters that are color blind (XX), daughters as carriers (XX), color blind sons (XY) and normal sons.