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    I don't remember much from GCSE biology (not a lot about genetics, anyway).

    But how is this possible:

    My four grandparents each had dark brown hair.
    My immediate family (parents and sister) also have brown/dark brown hair.

    Yet, all my life I have had blonde hair.

    Wut?
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    maybe your aunts or uncles had blonde hair or your ancestors.
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    Chances are, you were adopted or are not from the same family line
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    A parent would've been a carrier of the gene that makes your hair blonde I should think...
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    blonde gene is recessive
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    Parents are carriers, and it's a recessive gene :moon:
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    The simple version as I understand it from A level.

    Each person in your family carries 2 genes, one from each parent:
    B - brown - dominant
    b - blonde - recessive

    Therefore:
    BB - brown
    Bb - brown
    bb - blonde

    Therefore:
    You = bb
    Your sister = BB or Bb
    Your parents = Bb and Bb
    Your grandparents = at least one Bb on each side, the others BB.
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    you are adopted
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    Your parents are both carriers of the blonde gene. It's recessive, meaning it gives way to their dominant dark haired gene. You just happened to get the recessive gene twice.
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    Your parents both have a dominant allele (think that's what their called) that's brown and a recessive one that's blonde, causing both of them to be brown haired. They both passed on their recessive gene, meaning both your hair colour alleles are blonde so you're blonde.
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    (Original post by KayleeeWayleee)
    A parent would've been a carrier of the gene that makes your hair blonde I should think...
    Im with her ^^

    Or, your parents dropped you in some yellow carpaint when you were young, and tried to pass it off as blonde. It can happen.
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    Your parent have brown hair (which is dominant to blonde hair)
    But they could be carriers of the blonde hair gene - so (Br= brown, Bl= blonde :P Br Bl and Br Bl for your mother and father
    so that would mean there would been a 1 in 4 chance they would have a blonde child = you!
    • Thread Starter
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    Aha I remember about recessive genes!

    Makes sense. Means my grandparents on my dads side must have had Bb, for example, because my aunt has blond hair
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    Welcome Squad
    It's not that weird. First of all, like people have said, blonde hair is the recessive gene, so even if your parents carry it and passed it on to you, if they also have a brown gene they'll have ended up with brown hair.

    Also, peoples hair colour can very easily change. I was very blonde as a child but now I have brown hair.

    My husband's hair is very dark brown.

    Yet our son has hair so blonde he looks like Dennis!
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    Both of your parents will have been carries of a recessive allele for blonde hair. I could draw lots of confusing genetic diagrams, but I think that it would be a waste of time.

    Go to wikipedia and look up dihybrid crosses and Gregor Mendel's law of inheritance and all that jazz.
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    (Original post by Emanon)
    The simple version as I understand it from A level.

    Each person in your family carries 2 genes, one from each parent:
    B - brown - dominant
    b - blonde - recessive

    Therefore:
    BB - brown
    Bb - brown
    bb - blonde

    Therefore:
    You = bb
    Your sister = BB or Bb
    Your parents = Bb and Bb
    Your grandparents = at least one Bb on each side, the others BB.
    Looking at this makes me feel sick and reminds me why I failed so hard at A Level biology.
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    Ask the milkman/postman :cool:
 
 
 
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