The genes for ABO blood group is located on

Options

A. Chromosome 4
B. Chromosome 7
C. Chromosome 9
D. Chromosome 11

Answer

To determine the location of the genes for the ABO blood group, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the ABO Blood Group System**:
- The ABO blood group system consists of three alleles: A, B, and O.
- The presence of these alleles determines the blood type of an individual (A, B, AB, or O).

2. **Identify the Chromosomes**:
- The question provides four options regarding which chromosome the ABO blood group genes are located on:
- A) Chromosome 4
- B) Chromosome 7
- C) Chromosome 9
- D) Chromosome 11

3. **Research Chromosome Functions**:
- Chromosome 4 is known for different genes, but not for the ABO blood group.
- Chromosome 7 is the longest chromosome but does not contain the ABO blood group genes.
- Chromosome 9 is known to contain the genes responsible for the ABO blood group.
- Chromosome 11 has other functions and is not related to the ABO blood group.

4. **Select the Correct Option**:
- Based on the information gathered, the genes for the ABO blood group are located on **Chromosome 9**.

5. **Final Answer**:
- Therefore, the answer to the question is **Option C: Chromosome 9**.