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Homework Help: Hardy Weinberg Question

  1. Jun 9, 2012 #1
    1. The problem statement, all variables and given/known data

    In a population on fish, 40 have red eyes and 260 have blue eyes. Allele for red is dominant over blue alleles. Use hardy Weinberg principle to calculate the frequency of the white and red allele.

    2. Relevant equations

    p2 + 2pq + q2 = 1

    q + p = 1

    3. The attempt at a solution

    p = 96.67 %

    i took 40 and divided it by 300 and for 13.3% as my answer. but i got it wrong...I'm pretty much stuck, help?
  2. jcsd
  3. Jun 10, 2012 #2


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    Staff: Mentor

    Assuming p is the frequency of the dominant allele, can you use p & q to express what fraction of the population has red eyes?

    Note: [itex]\frac{40}{300}[/itex] is the fraction of the population with red eyes, but it is not equal to p.
  4. Jun 10, 2012 #3


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    Science Advisor
    2017 Award

    It is also helpful is to express the fraction of the population that has blue eyes in terms of q.
  5. Jun 10, 2012 #4


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    Staff: Mentor

    Good point. Much simpler than what I attempted to do.
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