COMPLETED WITH THANKS genetics

[sueky71]

is it possible for a mother to have 1 dark haired, brown eyed child and 1 blonde haired, blue eyed child, with the same father
i seem to recall from biology class that because the brown eye gene is always dominant that it was impossible for a brown eyed parent to produce a blue eyed child - is this right?

[Little Nell]

Heavens, I hope not - I have a brown-eyed husband and two off-spring: one brown eyed and the other blue eyed like me.   

You need to look further back to previous generations.  Brown-eyed is dominant, but if two recessive genes get passed on then you will get that trait come out.

Nell

[dollylee]

My nephew is blonde with blue eyes and his wife had brown hair and brown eyes.

They have two boys....one  blonde with blue eyes and one brown hair brown eyes.

I am sure the boys have the same father   so it might be rare but not impossible.

dollylee

[sueky71]

thanks to you both
i hope i didn't offend
i wasn't sure how to ask to question 'delicately' so i just blurted it out.
i too have 2 daughters, 1 dark hair, brown eyes and 1 blonde & blue eyes, but i know they have different fathers.
they reason i asked is that i've come across a document in the australian NA in which an ancestor applied for passage for himself and only one of his children (after his divorce) so i was just wondering out aloud.

[Little Nell]

No, you didn't offend at all.  But it is more complicated than at first appears.  My parents both have brown eyes, but two of their off-spring have blue eyes, while two have brown.  (And my parents have only been married the once  )  So previous generations have to come into play.

We won't even try to sort out the red-hair part 

Nell

[stanmapstone]

Why do I have blue eyes when both my mother and father have brown eyes?
See
http://www.sciencekidsathome.com/science_topics/genetics-a.html

Stan

[sueky71]

interesting link stan - had to read it a few times though before i 'got' it.
did you notice the several links to the DNA genealogy sites?
i watched a programme last night (forget which one!) where people on the orkney islands were DNA tested to see if they were descended from vikings or picts - fascinating stuff

[Springbok]

This link is a little more complicated, but described (fairly) well the experiments of Gregor Mendel in the late 1800's and his experiments with Peaplants.

I can remember that we were taught in Physics lessons in the 50's how the sequence went, but I've forgotten just how it goes.

The diagram explaing the 3:1 principal is probably the easiest.

Amazing to think how long ago that he found the basis of what is now recognised as the genetic inheritance'

http://anthro.palomar.edu/mendel/mendel_1.htm

Spring

[Cybermouse]

Why do I have blue eyes when both my mother and father have brown eyes?
See
http://www.sciencekidsathome.com/science_topics/genetics-a.html

Stan

Thanks for the link too, Stan. Hubby and I are living proof of brown eyed parents with a blue eyed off spring. Even questioned the midwife when she was born and told that our newborns eye colour would change to brown like ours as it was not possible to have a blue eyed daughter. Well................... her eyes are still as blue as the sky and she is now 7 years old!