Question

A child with blood group A has father with blood group B and the mother with blood group AB. Choose the option that gives the correct genotypes of father, mother, and the child:

• A. \( I^A i \) & \( I^B i \) & \( I^A i \)
• B. \( I^A I^B \) & \( I^A i \) & \( I^A I^A \)
• C. \( I^B i \) & \( I^A I^B \) & \( I^A i \)
• D. \( I^B I^B \) & \( I^A I^B \) & \( I^A I^A \)

Hint:

Blood group inheritance follows Mendelian principles, where the A and B alleles are dominant over the O allele. The child's blood group is determined by the alleles inherited from both parents.

Answer 1

The Correct Option is A

Blood Group Inheritance and Genotype Analysis 

Step 1: Understanding Blood Group Inheritance

Blood group inheritance follows Mendelian genetics. The genotypes are determined by the alleles inherited from the parents:

• Blood group A: Genotype IA i (A allele and O allele).
• Blood group B: Genotype IB i (B allele and O allele).
• Blood group AB: Genotype IA IB (both A and B alleles are expressed).

Step 2: Analyzing the Given Parental Blood Groups

Now, let's analyze the parental blood groups and their possible offspring:

• Father's blood group: B, so his genotype is IB i.
• Mother's blood group: AB, so her genotype is IA IB.
• Child's blood group: A, meaning the child must have inherited the IA allele. Therefore, the child’s genotype is IA i, receiving IA from the mother and i from the father.

Step 3: Conclusion

Thus, the genotypes of the father, mother, and child are:

• Father: IB i
• Mother: IA IB
• Child: IA i

Therefore, the correct answer is Option (A).