Co-dominance, Multiple Alleles,and Sex-linkage

1. Abby is unsure of the father of her daughter, Susie, and wantsa quick way to find out which of the men she has dated it could be.Her blood type is AB, and her daughter’s is B. Of the possible menDalton, has AB type blood, Jordan has O type blood, and Wyatt has Ablood. Use the clues here and for each part of this problem to seewho the father is. *** Be sure to answerall parts of each question.

• For blood type, A (I^AI^A orI^Ai) and B (I^BI^B orI^Bi) blood types are dominant to O (ii), and AB(I^AI^B) is codominant, meaning that both A andB proteins are expressed.
• The gene for color vision is sex-linked on the X chromosome,and having color vision (Females: X^BX^B orX^BX^b, Males: X^BY) is dominant tobeing color blind (Males: X^bY, Females:X^bX^b).
  1. Give the genotypes for eachindividual for blood type and then for color blindness. Youmay not be able to figure out all parts with the informationprovided. Put a “?” in the position for anyalleles that you cannot determine, but you should be able to put atleast part of the genotypes for all individuals based on theinformation provided above and additional information provided inthe problems below.
     1. Abby’s Genotypes
        1. Blood Type:
        2. Vision:
     2. Susie’s Genotypes
        1. Blood Type:
        2. Vision:
     3. Dalton’s Genotypes
        1. Blood Type:
        2. Vision:
     4. Jordan’s Genotypes
        1. Blood Type:
        2. Vision:
     5. Wyatt’s Genotypes
        1. Blood Type:
        2. Vision:

1. Can you tell from the information given in the word problemabove who the father is? Can you at least eliminate one man? Why orWhy not?

1. Wyatt insists that he cannot be the father. He provides hisparents’ blood types – both are AB. Is Wyatt correct that he is notthe father? How do you know? *Hint, do a cross for his parents anddetermine what his actual genotype is.

1. Abby is hoping that Dalton is the father. She argues thatbecause Dalton is the only man who color blind, just like Susie, hemust be the father. Who is the father (Can you tell?)? How do youknow or why can’t you tell?