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A question

Genetics as it applies to evolution, molecular biology, and medical aspects.

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A question

Postby bertstare » Tue Mar 13, 2012 5:33 pm

A white woman marries a black man.They have four children-2 sons and 2 daughters.What proportion of these children is likely to be black.

1-25%
2-50%
3-100%
4-none


Answer in the science General Knowledge book is 4.I want the explanation for this.
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Postby JackBean » Wed Mar 14, 2012 10:06 am

what is 4.1? None and 25%?

To my knowledge the skin color is not sex determined, thus, if we assume they parents are not mixed already, we should expect 50% (although it will be rather that all four children will be slightly black)
http://www.biolib.cz/en/main/

Cis or trans? That's what matters.
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Re: A question

Postby javedshaikm » Wed Mar 14, 2012 4:22 pm

As per my knowledge - let us assume
1) white woman(WWbb - gamete ) marries Black man (BBww - gamete)
then first generation would be(in normal case) -

White Daughter (WWBw) + White son (WwBw)

or

White Daughter (WWBw) + black son (BwBw)

So the percentage would be 25%
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Postby canalon » Wed Mar 14, 2012 7:26 pm

Do you really think that skin color in human is a single trait that is present or absent? If so I suggest that you get out of your home and walk on the streets for a few minutes...
Patrick

Science has proof without any certainty. Creationists have certainty without
any proof. (Ashley Montague)
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Re: A question

Postby wbla3335 » Wed Mar 14, 2012 10:38 pm

The question makes the assumption that the woman and the man are purebreds (hard to find these days). Any offspring between the two cannot therefore be purebred white or black (answer 4). As canalon implies, people aren't peas.
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