Jeferson asked in Science & MathematicsBiology · 6 months ago

# I have dark brown eyes. My DNA result gave me ''homozygous for blue eyes color''. What does that mean?

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• Anonymous
6 months ago

If your mom is Bb, and not BB, then you could be carrying the gene for blue eyes as a recessive gene. This means you are also a Bb, and could give the b to your child. I posted the math below:

Brown eye gene = B

Blue eye gene = b

Each person has two copies of the eye color gene in their genome, one inherited from each parent. Now if both parents only carry the gene for brown eyes, BB and BB, then their child will receive one B from each parent, ending up as BB. The same works for blue eyes, if that's the only gene both parents carry, bb and bb. Each parent gives one b to the child, who ends up bb.

If you have one parent who only has the gene for brown eyes, BB, and one parent who only has the gene for blue eyes, bb, then all the children, with no exceptions, will have brown eyes. Example: One parents gives a B, the other give a b. Bb always = brown eyes.

Here's why: When you have two alleles (coding sequences) from genes that are at odds with each other, one version will override the other. When dealing with eye color, B always dominates b. B is the dominant gene and b is the recessive gene.

But these children now carry the b gene in them, and could pass it down to their own children. Some of them, depending on the other parent, could end up with blue eyes.

If one parent has the recessive blue eye gene, meaning they are Bb, and the other parent only carries the gene for blue eyes, bb, then each time they have a child, there is a 50% chance it will have blue eyes. Example: First parent is Bb, and the second parent is bb, then their children will end up as one of the four listed here; Bb, bb, Bb, bb.

If both parents carry the gene for brown eyes and blue eyes, then each time they have a child, there is only a 25% chance it will have blue eyes. Example: First parent is Bb, and the second parent is Bb, then their children will end up as one of these four: BB, Bb, Bb, bb.

Lv 7
6 months agoReport

This 100% does not have anything at all to do with the question.

• 6 months ago

You carry the blue eyed gene.

• Zirp
Lv 7
6 months ago

it means somebody is oversimplifying things. Eyecolour is not a simply single-gene trait. It's quite possible that your iris is blue. It just doesn't show because the brown is more o the outside of your eye

• 6 months ago

It means the test didn't look at enough genes.

• Anonymous
6 months ago

Two copies of blue eyed genes. There's some other factor making yours brown.

• Anonymous
6 months ago

Blue eyes is the result of a lack of pigment inside the eye, since the eye's own molecules scatter blue light. The scattered blue light is absorbed by the pigments eumelanin (dark brown or black) or phaeomelanin (yellow to red) that is normally present inside the eyes. If those pigments are absent then your eyes will look blue.

Researchers found that the OCA2 gene in blue eyed folks are defective, and they fail to make the pigment eumelanin, resulting in blue eyes. However, the OCA2 gene mutation only accounts for 2/3 of the cases of blue eyes. Therefore there is really no single blue-eyed gene. Your DNA result did not say whether you are homozygous for the OCA2 gene mutation that is responsible for blue eyes. Therefore it is hard to say whether your report is wrong or not. Of course there are also cases in which people should have blue eyes but they do not. So. it is nevertheless possible that you are homozygous for blue eyes but you still have brown eyes. Sometimes the body works in mysterious ways. LOL