For ABO system of blood group in humans, allele I^A produces ______ enzyme.

Options

A. N- acetylgalactosamyl transferase
B. Glactosyl transferase
C. N- muramic transferase
D. NAG & NAM

Answer

To answer the question regarding the ABO blood group system in humans and the enzyme produced by the allele I^A, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the ABO Blood Group System**:
- The ABO blood group system is determined by the presence of specific antigens on the surface of red blood cells. The alleles involved are I^A, I^B, and i.

2. **Identifying the Allele I^A**:
- The allele I^A is responsible for producing blood group A. It encodes for a specific enzyme that modifies the sugar structures on the surface of red blood cells.

3. **Determining the Enzyme Produced by I^A**:
- The enzyme produced by the allele I^A is known as **N-acetylgalactosaminyltransferase**. This enzyme is crucial for adding the N-acetylgalactosamine sugar to the H antigen, which is the precursor for the A antigen.

4. **Conclusion**:
- Therefore, the correct answer to the question is that the allele I^A produces the enzyme **N-acetylgalactosaminyltransferase**.

### Final Answer:
For the ABO system of blood group in humans, allele I^A produces **N-acetylgalactosaminyltransferase**.

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