No, an O-group parent cannot have an AB-group child at all.
No. They can have an O positive, an O negative, A B positive, or a B negative child.
o positive
no
yes
If the mother is A negative, and the father is B positive, they could have children who are A negative, A positive, B negative, B positive, AB negative, AB positive, O negative, or O positive.
Given that the mother's DNA is A and the child is A positive, the father's DNA must also contain the A antigen. The father could be A positive, A negative, AB positive, or AB negative.
If mother is heterozygote yes.
I'm not sure how negative or positive is determined, but a B mother and O father can have a B child.
no
no
if your child is negative, i would ask for a blood sample from the mailman
yes.