O negative and a positive what what could baby have o positive what blood type can baby have

If : If you are asking if one parent has o negative and one parent has a positive blood; then the response follows. The simple part of this answer involves the ABO blood type. If the parents have type a, type b, or type o blood, the baby can have type o blood. The next part of the answer, which is referring to the rh factor is a little bit more complicated. The rh factor is on the surface of red blood cells. Rh positive (+) is dominant over rh negative (-). About 85% of people in the United States are rh positive. The parent who has o negative blood is (--) since rh negative is recessive. The parent with a positive blood could be (++) or (-+) since rh positive is dominant. If the baby gets an rh positive from one parent and an rh negative from the other parent, than the baby will be rh positive. If the baby gets an rh negative from each parent than the baby would be rh negative. It is extremely important to have blood types tested because when the mother is rh negative and the father is rh positive there can be complications. The short answer is: the baby could be either o positive or o negative.

The : The baby could be o+, o-, a+, or a-. All of these would be possible. The parent with o negative blood has two genes for type o blood (o/o). The parent with type a blood could be a/a or a/o. If the a parent is a/a then the baby will have type a blood (a/o). If the a parent id a/o, then it's 50/50 between type a and type o. See dr. Fowler's answer for the explanation about the rh factor (+ or -).

See below: If one parent is o+, and one is o-, the baby is definitely going to be type o. It might be + or - depending on the genetic mix during conception.