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Homework Help: Population Genetics: Inbreeding

  1. Mar 29, 2008 #1
    1. The problem statement, all variables and given/known data
    Dolor and her cousin Largo have conceived a child. They are very concerned about the baby, because they have heard that children of close relatives have a higher incidence of birth defects and/or inherited recessive disorders. They know that their maternal grandmother was a carrier of the Herrera syndrome allele. Assuming that this is the only source of genetic problems for Dolor and Largo, what is the chance that they are both carriers ?
    a. 1 in 16

    b. 1 in 4

    c. 1 in 8

    d. 1 in 106

    e. 1 in 2



    2. Relevant equations
    See below.


    3. The attempt at a solution

    Each grandchild has ¼ probability of carrying one of four original alleles from grandparents, so the probability of both being carriers is (¼)* (1/4) = 1/16?




    1. The problem statement, all variables and given/known data
    The chance that Dolor and Largo will have a child with Herrera’s
    syndrome is
    a. 1 in 4

    b. 1 in 64

    c. 1 in 32

    d. 1 in 16

    e. 1 in 12




    2. Relevant equations
    See below.


    3. The attempt at a solution
    For the great-grandchild there is a 1/8 probability (of gametes) for getting a recessive allele, so

    (1/8) * (1/8) = 1/64?


    Thank you for any help.
     
  2. jcsd
  3. Apr 4, 2008 #2

    Moonbear

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Everything sounds right.
     
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