The Blood Group Inheritance

Blood group inheritance follows a well-defined pattern based on the combination of genes inherited from both parents. The four main blood groups are A, B, AB, and O, which are determined by the presence or absence of specific antigens on the surface of red blood cells. Additionally, blood groups can also be Rh positive or Rh negative, depending on the presence or absence of the Rh antigen.

Understanding the Blood Group Compatibility

To understand which blood groups a couple with blood group AB and B cannot have a child with, it is important to consider the possible combinations of blood groups that can be inherited from each parent.

Parental Blood Types
- Parent 1: Blood Group AB
- Parent 2: Blood Group B

Possible Blood Group Inheritance

When considering the possible blood group inheritance, the ABO blood type system provides the following options:

1. Blood Group A:
- If Parent 1 passes the A allele (from the AB blood group) and Parent 2 passes the B allele (from the B blood group), the child can have blood group A.
- Thus, the couple can have a child with blood group A.

2. Blood Group B:
- If Parent 1 passes the B allele (from the AB blood group) and Parent 2 passes the B allele (from the B blood group), the child can have blood group B.
- Thus, the couple can have a child with blood group B.

3. Blood Group AB:
- If Parent 1 passes the A allele (from the AB blood group) and Parent 2 passes the B allele (from the B blood group), the child can have blood group AB.
- Thus, the couple can have a child with blood group AB.

4. Blood Group O:
- If Parent 1 passes the O allele (from the AB blood group) and Parent 2 passes the O allele (from the B blood group), the child can have blood group O.
- Thus, the couple can have a child with blood group O.

Conclusion

Based on the possible combinations of blood groups that can be inherited from a couple with blood group AB and B, it can be concluded that they cannot have a child with blood group AB. However, they can have a child with blood groups A, B, or O. It is important to note that this analysis only considers the ABO blood type system and does not take into account the Rh factor, which is a separate consideration in blood compatibility.