How many phenotype and genotypes are possible for ABO blood groups ?

Options

A. `{:("Phenotypes","Genotypes"),(4,4):}`
B. `{:("Phenotypes","Genotypes"),(6,4):}`
C. `{:("Phenotypes","Genotypes"),(4,7):}`
D. `{:("Phenotypes","Genotypes"),(4,6):}`

Answer

To determine the number of phenotypes and genotypes possible for the ABO blood groups, we can follow these steps:

### Step 1: Identify the Phenotypes
The ABO blood group system has four distinct phenotypes:
1. **A Blood Group**: Individuals with A antigens on the surface of their red blood cells (RBCs).
2. **B Blood Group**: Individuals with B antigens on the surface of their RBCs.
3. **AB Blood Group**: Individuals with both A and B antigens on the surface of their RBCs (co-dominance).
4. **O Blood Group**: Individuals with no A or B antigens on the surface of their RBCs.

**Total Phenotypes = 4**

### Step 2: Identify the Genotypes
The ABO blood group is determined by the I gene, which has three alleles: IA, IB, and i (the recessive allele). The possible combinations of these alleles lead to the following genotypes:

1. **AA (homozygous A)**: Results in A blood group.
2. **Ai (heterozygous A)**: Results in A blood group.
3. **BB (homozygous B)**: Results in B blood group.
4. **Bi (heterozygous B)**: Results in B blood group.
5. **AB (heterozygous AB)**: Results in AB blood group.
6. **ii (homozygous O)**: Results in O blood group.

**Total Genotypes = 6**

### Conclusion
Thus, for the ABO blood groups:
- **Phenotypes = 4**
- **Genotypes = 6**

### Final Answer
There are **4 phenotypes** and **6 genotypes** possible for the ABO blood groups.

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