Friday, June 18, 2010

Red hair and recessive and dominant genes?

I am confused about the facts about the recessive and dominant genes in red hair. I have had people tell me that red hair is a recessive trait, and both sides have to carry it for it to show up. I have also had people tell me that it skips a generation. I just want to know the facts so that when my child is born and it doesn't have the same dark red hair as my husband people, his mother mostly, who is convinced it's going to be a red haired child, can be set straight about the about the whole thing. Thanks.



Red hair and recessive and dominant genes?

"Red hair is not actually a recessive gene (like blonde is), but is rather an "incomplete dominant." In the world of genes, there are dominant genes, which take over any recessive gene (brown, black), recessive genes (blonde), which will be taken over by any dominant gene, or incomplete dominent genes (red). Incomplete dominant genes will "blend" with any dominant, recessive or other incomplete dominant gene. I, for example, have "auburn" hair, which is essentially red blended with brown. Strawberry blondes are red blended with blonde.



So you've got yourself a red headed parent (let's call those genes aa) and a blonde parent, which we'll represent as bb. 100% of the offspring will have one hair color gene from each parent, or ab. This means red and blonde. Since red will always blend with other genes, the resulting hair color should be a blend of blonde and red, or strawberry blonde. In the case of my parents, which both have brown hair (let's call the brown/black genes C), either one parent or possibly both are carrying one "a" in addition to their brown or black genes, with the possibility of even a blonde thrown in (CC, Cb, or Ca). My parents are probably (Ca, CC). I'm probably a Ca, or a blend of brown and red. This result has an outcome likelihood of 50%."



this is from http://www.science.ca/askascientist/view...



Red hair and recessive and dominant genes?

if i'm not mistaken, the dominant allele for hair colour is black. and the other colours are recessive. and it also true that it can skip generation. maybe ur husband is a heterozygous. and u dont carry the allele for red hair at all. so, maybe the characteristic will show up in ur grandchildren or their next progeny.



Red hair and recessive and dominant genes?

I think Triveni is giving you the right basic idea, except I think that hair color is a little more complicated than just one single pair of genes. But red definitely might blend with other light colors such as blond or light brown.



You should understand that recessives can skip more than one generation. A whole family of black haired folks can have only black haired kids for several generations, but then all of a sudden out pops a redhead. The genes were there all the time, but there had to be two parents who had the redhead gene and then there had to be some luck. This is why lots of families of Irish extraction or Scottish extraction can have three or four black haired kids from a black haired mom and dad, and then out pops the redhead!

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