The genotype of blood group 'A' is

Options

A. `I^(A)I^(A)//I^(A)I^(O)`
B. `I^(B)I^(B)//I^(B)I^(O)`
C. `I^(A)I^(B)`
D. `I^(O)I^(O)`

Answer

To determine the genotype of blood group 'A', we need to understand the genetics behind blood types.

### Step-by-Step Solution:

1. **Understand Blood Groups**: Human blood groups are classified into four main types: A, B, AB, and O. These blood types are determined by the presence of specific antigens on the surface of red blood cells.

2. **Identify Antigens**: Blood group 'A' has A antigens on the surface of its red blood cells. This means that the genotype must include the allele that codes for the A antigen.

3. **Genotype Options**: The possible genotypes for blood group 'A' are:
- Homozygous: I^A I^A (both alleles are A)
- Heterozygous: I^A I^O (one allele is A and the other is O)

4. **Analyze the Given Options**:
- Option A: I^A I^A (homozygous)
- Option B: I^B I^B (not applicable for blood group A)
- Option C: I^A I^B (not applicable for blood group A)
- Option D: I^O I^O (not applicable for blood group A)

5. **Determine the Correct Genotype**: Since blood group A can be either homozygous (I^A I^A) or heterozygous (I^A I^O), the correct answer for the genotype of blood group A is:
- **Option A: I^A I^A (homozygous)**
- **Option B: I^A I^O (heterozygous)**

6. **Conclusion**: The genotype of blood group 'A' can be either I^A I^A or I^A I^O. However, since the question specifically asks for the genotype without specifying homozygous or heterozygous, we can conclude that the most straightforward answer is I^A I^A.

### Final Answer:
The genotype of blood group 'A' is I^A I^A (homozygous) or I^A I^O (heterozygous).

---