Choose the correct option with respect to the genetic makeup of the ABO blood grouping system in humans.

Options

A. 4 Alleles, 4 phenotype and 6 genotype
B. 3 Alleles, 6 phenotype and 4 genotypes
C. 4 Alleles, 6 phenotype and 4 genotypes
D. 3 Alleles, 4 phenotypes and 6 genotypes

Answer

To solve the question regarding the genetic makeup of the ABO blood grouping system in humans, we will analyze the alleles, genotypes, and phenotypes associated with this system step by step.

### Step 1: Identify the Alleles
The ABO blood group system is determined by three alleles:
- **A** (IA)
- **B** (IB)
- **O** (i)

### Step 2: Understand the Genotypes
From these three alleles, we can form different combinations (genotypes) that determine an individual's blood type. The possible genotypes are:
1. AA (homozygous for A)
2. AO (heterozygous for A)
3. BB (homozygous for B)
4. BO (heterozygous for B)
5. AB (heterozygous for both A and B)
6. OO (homozygous for O)

Thus, there are a total of **6 possible genotypes**.

### Step 3: Determine the Phenotypes
The phenotypes (blood types) that can result from these genotypes are:
1. Type A (from AA or AO)
2. Type B (from BB or BO)
3. Type AB (from AB)
4. Type O (from OO)

This results in a total of **4 possible phenotypes**.

### Step 4: Conclusion
In summary, the ABO blood grouping system has:
- **3 alleles** (A, B, O)
- **6 genotypes** (AA, AO, BB, BO, AB, OO)
- **4 phenotypes** (A, B, AB, O)

Based on this analysis, the correct option regarding the genetic makeup of the ABO blood grouping system in humans is that there are 3 alleles, 4 phenotypes, and 6 genotypes.

### Final Answer
The correct option is: **3 alleles, 4 phenotypes, and 6 genotypes.**

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