[NancyKR]

Hi!

My dad has very curly hair and, with my very straight- haired mom had 4 curly haired kids. My curly haired self, along with my straight-haired husband produced 2 straight-haired kids. From what I've read, curly hair is dominant (although I did find a site that said it was recessive). I always expected to have curly-haired kids. Were 2 straight-haired kids what I could've expected?

Thanks!

[Eileen G]

You've got a straight haired mother and a straight haired husband. Straight hair was always on the cards.

[NancyKR]

You've got a straight haired mother and a straight haired husband. Straight hair was always on the cards.

Not necessarily. My dad had a straight haired mother and a straight haired wife and had 4 curly haired kids.

[Eileen G]

That's the point, it could go either way.

[Synnen]

Do you know how genetics work?

Curly hair is dominant, but that doesn't mean you don't carry the gene for straight hair as a recessive trait--your mom had straight hair. So... you have the genes Cs. Your husband's genes donate SS--no curly gene.

So--your kids have the chance of matching up with the following combinations:
S S
C Cs Cs

S ss ss

You literally had a 50/50 chance of either.

[NancyKR]

Do you know how genetics work?

Curly hair is dominant, but that doesn't mean you don't carry the gene for straight hair as a recessive trait--your mom had straight hair. So....you have the genes Cs. Your husband's genes donate SS--no curly gene.

So--your kids have the chance of matching up with the following combinations:
S S
C Cs Cs

S ss ss

You literally had a 50/50 chance of either.

Hey! That's just what my little Punnet square told me! Maybe I remember more from sophomore biology than I thought.

That would've been the same for my parent's kids too then. Funny how a 50/50 chance got my parents all of one and me all of the other. That's interesting.

Thanks! :)

[Eileen G]

It's the tossing a coin thing. No matter how often you toss it, it's still 50/50. The fact that you've just tossed ten heads in a row doesn't affect the chance of the next toss also being a head.

[elscarta]

Funny how a 50/50 chance got my parents all of one and me all of the other.

There are actually two possibilities for your father's genes. CC or Cs

If your father is Cs then the chance of having 4 curly haired children with your mother is 1 in 16 or 6.25%.

On the other hand if your father is CC then the chance of having 4 curly haired children with your mother is 100% as can be seen by the punnet square below.

C C
S Cs Cs
S Cs Cs

So it is much more likely that your father is CC.

With you and your husband, the chance of having 2 straight haired children is 1 in 4 or 25%.
The other possibilities are:
2 curly haired children - 1 in 4 or 25%
1 curly and 1 straight - 1 in 2 or 50%

[NancyKR]

This is EXACTLY what I wanted to know. Thanks! :)