Identify the tumour suppressor gene

Options

A. Oncogene
B. P53
C. Pseudogene
D. SRY

Answer

To identify the tumor suppressor gene from the given options, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Definitions**:
- **Oncogene**: These are genes that, when mutated or expressed at high levels, can lead to cancer. They promote cell growth and division, contributing to tumor formation.
- **Tumor Suppressor Gene**: These genes help regulate cell growth and division. They act as a brake on cell proliferation and can induce apoptosis (programmed cell death) when necessary.
- **Pseudogene**: These are segments of DNA that resemble functional genes but do not produce functional products; they are typically non-functional.
- **SRY Gene**: This gene is located on the Y chromosome and is responsible for determining male sex characteristics. It is not involved in tumor suppression.

2. **Evaluate Each Option**:
- **Oncogene**: Incorrect, as these promote cancer.
- **p53**: This is a well-known tumor suppressor gene, often referred to as the "guardian angel of the genome" because it helps prevent the formation of tumors by regulating the cell cycle and promoting apoptosis.
- **Pseudogene**: Incorrect, as these are non-functional genes.
- **SRY Gene**: Incorrect, as this gene is related to sex determination, not tumor suppression.

3. **Conclusion**:
- The correct answer is **p53**, as it is the only option that represents a tumor suppressor gene.

### Final Answer:
The tumor suppressor gene is **p53**.

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