Never. Although, genes for ABO and Rh blood groups are present on the surface of RBCs but ABO and Rh blood group systems are different. Rh positive is always dominant to Rh negative gene irrespective of ABO blood groups. Hence, Rh positive blood group always express itself.
If both parents are O negative and O positive, their children may inherit various blood types depending on their parents' genotype. However, all children will carry at least one O antigen in their blood type. The parents could have children with blood types O negative, O positive, A negative, A positive, B negative, B positive, AB negative, or AB positive.
If both parents are B- they can only have children who are B- and O-. One would have to be positive in order to have a child with positive blood.
Only if he's adopted. Parents with a + blood type can have children with a - blood type, but parents with an O bloodtypes can only have O type children together.
If they are both O negative, no, the child will be O negative.
Yes.
No, they will have a O negative child.
No - if both parents have blood type O, then the only possibility for their children is also blood type O. If they are both heterozygous for Rh (+/-) then they could have either + or - children. If either of them are homozygous (Rh+Rh+) then all the children will be +.
The possibilities include B positive, B negative, O positive, O negative.
No. If both parents have type O blood then they will only be able to have children with type O blood.
Nope, the baby will be O positive as well.
A or O positive or negative
No