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Homework Help: Genetics: Colorblindness and Blood Type

  1. Jul 6, 2010 #1
    1. The problem statement, all variables and given/known data

    A colorblind man with blood type AB marries a woman with normal vision and blood type A who is heterozygous for both traits. What are the odds of having a daughter that is colorblind and has blood type A?

    2. Relevant equations

    Xc Y IA IB x XC Xc IA i


    3. The attempt at a solution

    Dont know if it is 2/8=1/4 or 2/16=1/8
     
  2. jcsd
  3. Jul 7, 2010 #2
    Since these traits are not linked.. it might be easier to visualize these crosses as separate then bring the information together at the end. If we cross the Xc Y x XC Xc, then (1/4) of the offspring to be colorblind females. If we cross the blood types IA IB x IA i, then we get (1/2) of the offspring to be blood type A.

    Since the target phenotype was a female that was color blind AND blood type A... we multiply the answers.

    (1/4)(1/2)= (1/8) will be colorblind type A females <----- Final Answer
     
  4. Jul 7, 2010 #3
    thanks for the explanation...i understand it even better now!!
     
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