A woman with blood 'O' has a child with blood group 'O'. She claims that a man with blood group 'A' as the father of her child. What would be the genotype of the father, if her claim is right

Options

A. |O|O
B. |A|B
C. |A|O
D. |B|O

Answer

To determine the genotype of the father in this scenario, we need to analyze the blood groups and their corresponding genotypes.

### Step-by-Step Solution:

1. **Identify the Genotype of the Mother:**
- The woman has blood group 'O'. The genotype for blood group 'O' is represented as **ii** (or **IOIO**). This means she has two recessive alleles for blood type.

2. **Identify the Genotype of the Child:**
- The child also has blood group 'O'. Therefore, the child's genotype is also **ii** (or **IOIO**).

3. **Identify the Genotype of the Father:**
- The man has blood group 'A'. The possible genotypes for blood group 'A' are **IAIA** (homozygous) or **IAi** (heterozygous).

4. **Determine the Possible Genotypes from the Parents:**
- The mother (genotype **ii**) can only contribute an **i** allele (since she has two recessive alleles).
- For the child to have blood group 'O' (genotype **ii**), the father must also contribute an **i** allele.

5. **Conclusion on the Father's Genotype:**
- Since the father must contribute an **i** allele for the child to have blood group 'O', the only possible genotype for the father, while still being blood group 'A', is **IAi** (heterozygous). This means he has one 'A' allele and one 'O' allele.

### Final Answer:
The genotype of the father, if the woman's claim is right, would be **IAi**.

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