What blood type will a baby have with b negative mother and positive father?

When a B- mother and a positive father have a child, the child can have one of two blood types: B positive or B negative.

The mother's blood type is B-, which means she has the B antigen on her red blood cells but does not have the Rh factor (D antigen). The father's blood type is positive, which means he has the Rh factor on his red blood cells.

When a B- mother and a positive father have a child, the child can inherit either the B antigen from the mother or the Rh factor from the father. If the child inherits the B antigen, they will have B positive blood. If the child inherits the Rh factor, they will have B negative blood.

The probability of the child having B positive blood is 50%. The probability of the child having B negative blood is also 50%.