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.
· 3 months ago