Question

Two brown-eyed parents have produced three blue-eyed sons. If they have another child, how likely is it that the child will be brown-eyed

Answer 1

If two brown-eyed parents have produced three blue-eyed sons and if they have another child, it's likely their next child will be brown-eyed. Both parents have a recessive allele for blue eyes, so it is a 75 percent chance the next will be brown-eyed.

Hope that helps. -UF aka Nadia

Answer 2

Answer:

$75$%

Explanation:

Two brown-eyed parents have produced three blue-eyed sons . This means that the parents have heterogyzous genotype with one blue allele. Here, brown color is dominant over the blue color of the eye.

Let, the brown color eye allele be represented by "B" and the blue color allele be represented by allele "b"

So the genotype of parents would be "Bb"

If a cross is carried out between two parents with genotype "Bb" the following offspring will be produced  -

Bb x Bb

BB, Bb, Bb, bb

So out of the four offspring three children have brown color eye.

Thus the probability of a child having brown color eye is

$\frac{3}{4} * 100\\= 75$%