The largest known human gene is

Options

A. Option1 Gene for dystrophin
B. Option2 Gene for ADA
C. Option3 Gene for cystic fibrosis
D. Option4 Gene for phenylalanine hydroxylase

Answer

To solve the question regarding the largest known human gene, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question asks for the largest known human gene among the given options.

2. **Identify the Options**: The options provided are:
- Gene for dystrophin
- Gene for ADA (Adenosine Deaminase)
- Gene for cystic fibrosis
- Gene for phenylalanine hydrolase

3. **Research Each Gene**:
- **Gene for Dystrophin**: This gene is responsible for producing dystrophin, a protein that helps keep muscle cells intact. It is known to be the largest human gene.
- **Gene for ADA**: This gene is involved in the immune system and is much smaller than the dystrophin gene.
- **Gene for Cystic Fibrosis**: This gene is responsible for cystic fibrosis transmembrane conductance regulator (CFTR) and is also smaller than the dystrophin gene.
- **Gene for Phenylalanine Hydrolase**: This gene is involved in the metabolism of phenylalanine and is smaller than the dystrophin gene as well.

4. **Compare the Sizes**: The dystrophin gene spans about 2.3 megabases, which is significantly larger than the other genes mentioned.

5. **Conclusion**: Since the dystrophin gene is the largest among the options provided, we can conclude that the answer to the question is the gene for dystrophin.

### Final Answer:
The largest known human gene is the **gene for dystrophin**.

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