Which of the following gene is absent in a normal cell?

Options

A. Proto-oncogene
B. Tumor-suppressor gene
C. Gene related to program cell death
D. Oncogene

Answer

To answer the question "Which of the following gene is absent in a normal cell?", we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Normal Cells**:
- A normal cell is defined as a cell that is not cancerous and maintains regular functions and growth patterns.

2. **Identifying Gene Types**:
- **Proto-oncogenes**: These are normal genes that can become oncogenes when mutated or expressed at high levels. They are present in normal cells.
- **Tumor Suppressor Genes**: These genes help control cell growth and prevent uncontrolled proliferation. They are also present in normal cells.
- **Apoptosis-related Genes**: These genes are involved in programmed cell death, which is a normal process in cell lifecycle. They are present in normal cells.
- **Oncogenes**: These are mutated forms of proto-oncogenes that lead to cancerous growth. They are typically not present in normal cells.

3. **Conclusion**:
- Since oncogenes are associated with cancer and are not found in normal cells, we can conclude that the gene that is absent in a normal cell is the **oncogene**.

4. **Final Answer**:
- The correct answer is **oncogene**.