If I select a donor with a certain physical feature, what is the chance his offspring would inherit it?
The answer is not clear. A child’s appearance will often resemble some features of both parents but it is not predictable which features those will be.
I would like my baby to have a certain eye color, can I select a donor that makes that more likely?
Yes you can select a donor to make it more likely, but it is not guaranteed. Eye color does not follow a strict pattern of inheritance. A general rule is that the color brown is dominant while the color blue is recessive. It appears that two genes determine eye color. One gene comes from each parent. A parent can have brown eyes and have one brown gene and one blue gene (brown is dominant and ‘masks’ the blue gene) or two brown genes. A person with blue eyes often has two blue genes. We don’t always know what the genes are just by looking at the eye color in an individual. A person with hazel or green eyes may be any combination of brown and blue genes. Also, eye color can also change as a child grows older as some with light colors become darker with age. It is not uncommon to see a blue eyed child when both parent have brown eyes. It is less common to see a dark eyed child from parents who both have blue eyes but it is possible.
