If a baby's father has blue eyes and the mother has brown, what are the odds of the baby having blue eyes?

Answer 1

It will vary depending on what genes the brown-eyed mother carries.

The father carries two blue genes, because blue is the most recessive of traits and requires 2 blue genes.

The mother may carry 2 brown genes, or may carry 1 brown gene and 1 blue gene, green gene, gray gene or even violet gene (I guess it's a variation of blue, but think of Liz Taylor).

If the mother carries 2 brown genes, the odds of the child having blue eyes is 0, because each parent contributes one gene to the child. Since blue eyes require 2 blue genes, this scenario would make a blue-eyed child impossible.

If the mother carries 1 brown gene and 1 blue gene, I believe it's a 50-50 shot, but I'm fuzzy on it - brown is dominant, but as I recall it's strictly chance as to which is passed on. Father would absolutely pass on a blue gene, mother has 50-50 chance of sending on blue or brown gene. If she sends a brown gene, child will definitely be brown-eyed.

That's the best I can do :)

EDITED TO ADD: My husband has brown eyes, I have blue. My first daughter has blue eyes, my second has brown. His father has blue eyes, his mother has brown, so he obviously carried a blue gene, which my first daughter got.

Answer 2

The gene for brown eyes is dominant to the gene for blue eyes. To make the odds easier to work out you will need to tell us what colour eyes the baby's grandparents have on both sides.

If either of the mothers parents have blue eyes, the odds increase dramatically.

With the knowledge you have given us it is a 1 in 4 chance approximately. If the mothers parents have blue eyes this increases.

Answer 3

If really depends on who has the stronger genes. My father had blue eyes when he was young. As he got older they turned Green. My mother has always had brown eyes. I was born with blue eyes, then when I became a teenager they turned Hazel now they are Light Brown. So it's like a 50-50 chance.

Answer 4

It really depends. Blue eyes are a recessive trait, and brown eyes are dominant. I'd say there is more of a chance of the child getting brown, or green eyes even, depending on the brown-eyed parent's parents.

To get the blue eyes, both genes must carry "blue-eyes." any other combination of the two genes will result in something other than blue eyes.

Answer 5

depends whether the mother is homozygous for brown, i.e. she carries two genes for brown, in that case, 50/50, but if she is heteroxygous, carries one brown gene and one blue, then as the father MUST have two blue genes as the blue gene is recessive, then there is a 75/25 chance that the baby will have blue eyes. Unfortunately eye colour is not determined that simply.

Answer 6

I would say the chances are unlikely but not impossible. Brown eyes are dominant genes. Blue eyes are not only recessive but considered rare. It's not impossible but it's more likely the baby will have brown eyes.
My father has brown eyes and my mother has blue eyes. Both me and my sister have green eyes. Isn't that weird?

Answer 7

it would count thoroughly on the full-grandparents actual. If any of them had blue eyes there is an chance that they surpassed the recessive gene down and it would want to teach up. Say "B" represents brown eyes and "b" represents blue. If recessive "b" become surpassed down by using an concepts-blowing-grandparent to their baby they might have Bb genes, in different words, they convey the blue eye trait yet because brown is dominant it shows up. Then if that ascertain provides their baby the blue eye trait and the better 0.5 also includes the "b" trait, they're both Bb, then technically they could both bypass the recessive to their baby. even if, seeing because the mum is 0.5 hispanic and 0.5 cherokee, possibilities are extreme she doesn't carry any recessive. the purely desire for non-brown eyes is that if the daddy passes a recessive and the toddler, being a Bb, expresses both features as a eco-friendly or hazel colour. yet i'd say that its an truly small hazard if any in any respect.

Answer 8

50/50 but our 2 kids both have blue eyes and I have blue eyes and their dad has brown eyes. The baby can be born with blue eyes and can change colour before they are a year old apparently

Answer 9

I dont know, but my Dad has brown eyes and my Mom has green eyes and somehow I got blue eyes. So I would say its a good possibility the baby could have blue eyes.

Answer 10

1 in 4 (or 25%). This is because the gene for blue eyes is recessive so if the baby is born with a gene for blue eyes and a gene for brown, it will have brown eyes.