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Homework Help: Another bio question

  1. Feb 19, 2006 #1
    Hi... I just completed this assignment but i'm not sure if i did it correctly or not.. can someone review my assignment?

    9. Hand- in question: A brown-eyed man whose father was brown-eyed and whose mother was blue-eyed married a woman whose father and mother were both brown-eyed. The couple has a blue-eyed son. For which of the individuals mentioned can you be sure of the genotypes? What are their genotypes? What genotypes are possible for the others?

    1 = brown eye man
    2 = his father
    3 = his mother
    4= his wife
    5= wife’s father
    6 = wife’s mother
    7 = brown eyed man’s son

    1 = Bb
    2 = B? / he can be Bb or BB
    3 = bb
    4 = b? / she can be bb or Bb
    5 = B? / he can be Bb or BB
    6 = B?/ she can be Bb or BB
    7 = bb

    However, one should note that wife’s father and mother, both cannot be BB because the son is blue-eyed meaning that the wife is blue-eyed.
  2. jcsd
  3. Feb 19, 2006 #2


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    Everything is fine until your last sentence. As you got correct in #4, the wife has one allele for blue eyes, but could be either homozygous or heterozygous, so you cannot know if she is blue-eyed or brown-eyed.
  4. Feb 19, 2006 #3


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    Yes i concur, it looks good up to your last line. But you already stated correctly in #4 that "his wife" is either bb or Bb. You also already know that Bb is brown eyes (as in #1) and bb is blue eyes (as in #7). So I suspect your last sentence was an oversight.

    Although you solution does summarize the information needed to answer your questions, I suspect you are not going to hand in your answer in this form. Often teachers would like to see each question addressed individually.

    Last edited: Feb 19, 2006
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