If each parent is brown-eyed with a recessive blue-eyed gene, what is the probability of having a brown-eyed child? A blue-eyed child?

Brown eyes + blue eyes = 50% chance of blue eyes, but only if the brown-eyed parent carries a blue-eyed gene. If not, the chance is 0% Brown eyes + brown eyes = 25%, but only if both parents carry the blue-eyed gene.

a 25% If both of you have brown eyes, then there is generally a 25% chance that the baby will have blue eyes if both of you carry the recessive blue-eye gene. But if only one of you has a recessive blue-eye gene, and the other has two brown, dominant genes, then there is a less than 1% chance of the baby having blue eyes.