A Genetics Question

So I have a question on heredity...

If you have a redhead and a brunette who have a child, is there any possibility that they could have a blond? I know that brunette is dominant and blond is recessive, but where does red fit it? Would it mask a blond allele? Or is blond more dominant than red?

Thanks.

 

blond is more dominant than red. So a brunette could be brunette dominant and blond reccessive and a redhead red dominant and red reccessive (or something more reccessive than red). If the brunette passes on the reccessive blond gene and the redhead either of his/her genes, the blond would be dominant and the child would be blond.

I think

 

I've heard of blond parents getting a dark haired child...Makes you wonder if the father was really the father .

But I think it is possible. It just depends on the genes the parents carry and which they transfer to their child.

 

I know that brunette is dominant and blond is recessive, but where does red fit it?

I'm not quite sure, but I think that red is even more recessive than blond (only about 5% (??) of the world's population are redheads). So yes, if the brunette had a blond parent, the child can be blond, too.

My father has brown hair and my mother black, but I have 2 blond brothers (and my mother's father had red hair and my grandmother had black).

For a red haired child (like the son of my cousin) both parents need to have at least one red haired parent (my cousin and her husband are both blond).

Do I make any sense?

 

If brunette is dominant, and both parents were blond, how could they have a brunette child? In order to make a brunette child one would need to have a brunette gene, and that would make them a brunette too.

I think what you probably saw was what happened to me from living in the NorthEast - I was born blonde, and I'm still *technically* blonde (according to my hair dresser, but not most men), but my hair is dark enough blonde to look like a light brown.

No, it's much more likely that two brown-haired or brown-eyed parents would produce a blond-haired, blue-eyed kid, because both could have different dominant and recessive alleles. My best friend in high school was copper-haired, and both her parents were very dark-haired Italian. It was the recessive Northern Italian genes combined from both sides that gave her red hair.

Jae

ED: Well, I've been looking for the answer to how blond parents could have a brunette child, and I'll get back to you when I find a clear answer. Right now I found one that said each blonde has varying degrees of brunette in their genes. If two dirty blonds have a kid, he'd be more likely to be brunette than if two white-blonds had a kid, because the white blonde is apparently more recessive. It beats the hell out of me, so don't take my word for it. I'll be looking up Punnet Squares for now . . .

 

Let me ask my friend and get back to you. She's crazy at this genetics stuff.

 

Okay... But could a brunette and a redhead have a blond child?

Or would that be impossible since the redhead can't contribute a dominant gene? It would either be masked by the brunette gene or the blond gene contributed by the brunette parent?

I'm confused.

 

It should be possible.

My friend is a red-head and his parents are blond and brown-haired.

EDIT: Neg that. His mom dyes her hair.

 

I'm fairly certain that it would be possible. Both red and blonde are recessive, but I don't think either is recessive to the other. Two alleles are responsible for hair color, one that codes for red pigmenting and another that codes for the amount of pigments in the hair.

So I think it could work, but the brunette would have to be heterozygous and have a warmer tone.

Hope that made sense . . . just what I remember from biology class. Please correct me if I goofed.

 

Okay... But could a brunette and a redhead have a blond child?

I think we all agree to answer that question with yes.
Does anyone contradict?

 

If both parents have a blond allele? then it is posible for them to have a blond haired childeven if neither is blond themselves.

 

It should be possible. So let's say this:

B = brunette
b = blonde
r = redhead.

So the brunette parent, for the sake of argument, is Bb, brunette with a recessive blonde gene. The redhead parent would be rr, both recessive alleles. If you cross them, you get a nifty fifty-fifty chance for either brunette Br (with redhead recessive) or blonde br (with redhead recessive).

Or so I think, from freshman year biology. Stupid Mendel.

 

If two blond haired people have a dark haired child, either one of them is NOT the parent, or we should be examining their hair roots for evidence of dye

 

Keep in mind that a child can inherit traits from relatives generations back, it's not limited to their parents.

Both of my biological parents are brown haired and my brother and I are blonde. It happens.

 

That has nothing to to with Fan Resources!!!

 

Both of my biological parents are brown haired and my brother and I are blonde. It happens.

Yes, two dark haired parents can produce a blond child if each carries a recessive gene for blond hair, but if two blond haired people produce a dark haired child this can only take place if a mutation occured, otherwise parentage needs to be called into question.

And, this can be relevant for fan fiction if someone wants to use this info for creating background or story lines.

 

Regardless of dominance and recessiveness, hair color is regulated by polygenic inheritance, meaning several thousand alleles affect one trait. It is much more complex than simple Mendellian genetics. It's how two parents with dark (dominant) hair can have a fair headed child. The parents' ethnicity and the genes of *their* parents all play a role. For example, my father and his ex-wife have black hair. Two of their kids have black hair, and one has blonde.

My mother and her ex-husband have brown hair. Their two sons have brown hair. I, a product of her and the black haired father mentioned above, have red hair, like my maternal grandmother. Go figure.

 

My father's father was a redhead, and his mother was a brunette, and his hair was blonde. So yes

 

It's much more complex than blood type or the sex of the child. We never went into this in my biology class in the segment on genetics mostly because it was so complex!

 

Yes, its very complex, and we did go into it when I was in biology, but that was years and years and years ago.

Essentially, every human being carries genes for every eye and hair color. That's putting it simplistically, but truthfully. Families with repetitive instances of certain combinations are far more likely to continue that line of combinations than one that isn't. Predilection towards birthing twins is another trait that follows this pattern.

However it is possible for very odd and out of place combinations to come about. There have been blonde haired, blue eyed Chinese people born to two Chinese parents. They are extremely rare, perhaps one in two or three billion, but they do happen, occasionally.

Some combinations are so rare in a blood line that they are all but impossible...but it all depends on predilection and repetitive sequencing.

 

*drags out the biology text*

Hair colours other than pure blond or pure red are polygenic.

Blond hair is recessive.

Red hair is recessive and is expressed only if the individual is also homozygous for blond hair. (This means that the individual has bb for blond hair and also has the rr for red hair)

Also, the degree to which a specific pattern of genes is expressed varies from person to person. So, put simply, two people with Bb (Brown, blond) would both have brown hair but it may be of different shades (remembering that it is polygenic so it isn't quite that simple).

So . . . although it doesn't exactly say that a brunette and red head parents could have a blond child, it's likely possible. I don't know for sure, mind you, but I think for the purposes of fanfic it could be allowed.

~Abby~

 

However it is possible for very odd and out of place combinations to come about. There have been blonde haired, blue eyed Chinese people born to two Chinese parents. They are extremely rare, perhaps one in two or three billion, but they do happen, occasionally.

- I'm pretty sure that those are albinos. Which is a whole separate issue.

 

Yeah, polygenic inheritence. Which is why I have very light brown hair, but both my parents have pretty dark hair.

If you're talking redhead and brunette, may I ask for the characters - assuming that they're not OCs? But I have a hunch that I know who they are.

Knowing who they are could be helpful for any type of specific info.

 

Hi Musical!

The quick answer is yes, it is possible for a brunnette and a redhead to have a blond. But as others have said, it isn't as straight forward as simple mendialian genetics. Hair color is polygenic, and each gene has 2 or more alleles, so it gets hairy (sorry, bad pun ) quickly. There are at least 3 genes so far linked to brown hair, and both blonde and red hair are thought to be separate genes where the blonde allele or red allele are recessive to whatever the dominant color is (most likely brown, but it isn't known). Besides pigment color there are additional genes controlling how much pigment is actually produced. That said, it would be unlikely that someone with really dark brown or black hair would have a blonde child...not impossible, but unlikely. It would be more likely if the person with the brown hair is a medium brown. Also, if the red is carrot red rather than an more of an auburn color, then its more likely the child would be strawberry blonde or carrot red than truly blonde.

-K'Tai
Edit: Typo