How do you draw a punnett showing all the possible blood types for the offspring produced by a type "O" mother and an a Type "AB" father?
There are different notations for human blood types, so you may also see the IA, IB, and i system. Either way though, this particular cross produces a 1:1 ratio of A:B blood types in the offspring.
Because the O allele is recessive, it will be covered by either the A or B allele. So you would expect a 50:50 chance of each child having blood type A or blood type B, but they would have no chance of being blood type AB or blood type O.