Which of the following is incorrect about reporter gene

Options

A. gene whose phenotype can be assayed in a transformed origanism
B. `beta`- galactosidase gene is an example of reporter gene
C. test gene that is fused to the upstream region of cloned gene
D. None

Answer

To determine which statement about reporter genes is incorrect, we need to analyze the provided options one by one.

### Step-by-Step Solution:

1. **Understanding Reporter Genes**:
- Reporter genes are genes that are used to indicate whether a certain gene has been successfully expressed in a transformed organism. They provide a measurable output (phenotype) that can be easily observed.

2. **Analyzing Option 1**:
- The first option states that a reporter gene is a gene whose phenotype can be assigned in a transformed organism.
- **Evaluation**: This statement is correct because reporter genes are indeed used to indicate the expression of other genes by producing a visible phenotype.

3. **Analyzing Option 2**:
- The second option mentions that the beta-galactosidase gene is an example of a reporter gene.
- **Evaluation**: This statement is also correct. Beta-galactosidase is commonly used as a reporter gene in molecular biology to indicate gene expression.

4. **Analyzing Option 3**:
- The third option states that the tested gene is fused to the upstream region of the cloned gene, indicating that the reporter gene helps to identify the cloned gene.
- **Evaluation**: This statement is correct as well. Reporter genes are often fused to the promoter of a gene of interest to monitor its expression.

5. **Analyzing Option 4**:
- The fourth option claims that all three previous statements are correct.
- **Evaluation**: Since all previous options are indeed correct, this statement is also correct.

6. **Conclusion**:
- Since all the provided options (1, 2, and 3) are correct, option 4, which states that all three are correct, is also correct. Therefore, there is no incorrect statement among the options provided.

### Final Answer:
All the statements about reporter genes provided in the options are correct. Therefore, there is no incorrect statement regarding reporter genes.