The genotype of blood group O is

Options

A. 1)`I^(A)I^(A)//I^(A)I^(O)`
B. 2)`I^(B)I^(B)//I^(B)I^(O)`
C. 3)`I^(A)I^(B)`
D. 4)`I^(O)I^(O)`

Answer

To determine the genotype of blood group O, we need to understand the genetics of blood groups. Blood groups are determined by the ABO blood group system, which involves three alleles: IA, IB, and IO.

### Step-by-Step Solution:

1. **Understanding Blood Group Genetics**:
- The ABO blood group system consists of three alleles:
- IA (which produces antigen A)
- IB (which produces antigen B)
- IO (which produces no antigens)

2. **Identifying Blood Group O**:
- Blood group O is characterized by the absence of both A and B antigens on the surface of red blood cells.
- Therefore, individuals with blood group O do not have either IA or IB alleles.

3. **Genotype of Blood Group O**:
- The only genotype that can result in blood group O is when both alleles are IO.
- This means the genotype for blood group O is IO IO.

4. **Evaluating Options**:
- Let's evaluate the options provided:
- Option 1: IA IA (This is the genotype for blood group A)
- Option 2: IB IB (This is the genotype for blood group B)
- Option 3: IA IB (This is the genotype for blood group AB)
- Option 4: IO IO (This is the genotype for blood group O)
- The correct option is Option 4: IO IO.

### Final Answer:
The genotype of blood group O is **IO IO**.