posted by laurie .
If a brown-eyed man marries a blue-eyed woman and they have ten children, all brown-eyed, can you be certain that the man is homozygous? If the eleventh child has blue eyes, what will that show you about the father’s genotype?
It is very likely, but not certain. If the eleventh child has blue eyes, barring adultery, he must be heterozygous.
it is possible that he would be homozygous but not ccertain because some males have an extra chromosome foe example : the normal male has "XY" and another male may have "XXY" which means its possible for a male to be heterozygous but its not common.
Now if the eleventh child has blue eyes then that shows that the man's genotype is homozygous for brown-eyes , when u work out the cross these are the phenotypes "XB Xb, XB Xb, Xb Y, Xb Y" so the chances that the child has blue eyes or brown eyes are 50/50 ( Let 'b' represent blue eyes, recessive and Let 'B' represent brown eyes,dominant