| MadSci Network: Genetics |
Greetings,
Widow's peak is inherited as a dominant trait. This means that a person
with a widow's peak either has one or two copies of the allele (gene form)
specifying the trait.
Let's call "W" the allele for widow's peak, and "w" as the
allele for straight hairline. Since we each have two copies of each gene,
a person with widow's peak can have either Ww or WW. A person with a
straight hairline must have ww because if they carried the W allele, they
would have a widow's peak.
Each parent contributes one copy to their offspring. A Ww parent will have
a widow's peak, but be able to contribute either the W allele for the widow's
peak, or the w allele for straight hairlien, to their offspring. If both
parents are Ww (have widow's peak) but they EACH contribute their w allele to
the offspring, then the offpring will have a straight hairline.
So the answer to your question is, yes, a couple, both having widow's
peak, can have an offspring with a straight hairline. If you know a little
bit about statistics, you can even figure out the probability of the
occurance.
More about widow's peak:
http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=194000
More about inheritance:
http://w
ww.uic.edu/classes/bms/bms655/lesson3.html#DOMINANT
http://www.upei.ca/~cidd/howare.
htm
Cheers,
Sanjida
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