Genotype of A-group father of O-group child would be

Options

A. `I^(A)I^(A)`
B. `I^A i`
C. `I^(A)I^(B)`
D. ii

Answer

To determine the genotype of an A-group father who has an O-group child, we need to understand the inheritance of blood groups and the genotypes associated with them.

### Step-by-Step Solution:

1. **Understanding Blood Groups:**
- Blood groups are determined by the presence of specific antigens on the surface of red blood cells. The main blood group alleles are A, B, and O.
- The possible blood groups are A, B, AB, and O. The genotypes for these blood groups are:
- Blood group A: Genotype can be either IAIA (homozygous) or IAi (heterozygous).
- Blood group B: Genotype can be either IBIB (homozygous) or IBi (heterozygous).
- Blood group AB: Genotype is IAIB (co-dominance).
- Blood group O: Genotype is ii (homozygous recessive).

2. **Analyzing the Father’s Genotype:**
- The father is A-group, which means his genotype could be either IAIA or IAi.
- Since the child is O-group (genotype ii), we need to consider what genotypes can produce an O-group child.

3. **Crossing the Genotypes:**
- If the father’s genotype is IAIA (homozygous A), he can only pass on the IA allele. Therefore, he cannot have an O-group child because the child would inherit at least one IA allele from him.
- If the father’s genotype is IAi (heterozygous A), he can pass on either the IA allele or the i allele. The mother must have the genotype ii (O-group) to contribute the i allele.

4. **Conclusion:**
- The only way for an A-group father to have an O-group child is if his genotype is IAi. Therefore, the genotype of the A-group father of an O-group child is **IAi**.

### Final Answer:
The genotype of the A-group father of an O-group child would be **IAi**.