Genes in the normal cells which when activated lead to oncogenic transformation are called

Options

A. Viral oncogenes
B. Carcinogens
C. Protooncogenes
D. Cellular genes

Answer

To answer the question, "Genes in the normal cells which when activated lead to oncogenic transformation are called," we will analyze the options provided and identify the correct term.

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about specific genes that are found in normal cells and, when activated, can lead to cancer (oncogenic transformation).

2. **Analyzing the Options**:
- **Viral Oncogenes**: These are genes derived from viruses that can cause cancer. Since the question specifies "normal cells," this option is not applicable.
- **Carcinogens**: These are substances or agents that can cause cancer, but they are not genes. Therefore, this option is also incorrect.
- **Cellular Genes**: This term is too broad and does not specifically refer to the genes that lead to oncogenic transformation.
- **Proto-Oncogenes**: These are normal genes present in cells that help regulate cell growth and division. When mutated or overexpressed, they can become oncogenes, leading to cancer.

3. **Identifying the Correct Answer**: Since proto-oncogenes are the genes in normal cells that can lead to oncogenic transformation when activated or mutated, the correct answer is **Proto-Oncogenes**.

4. **Conclusion**: The genes in normal cells that, when activated, lead to oncogenic transformation are called **Proto-Oncogenes**.

### Final Answer:
**Proto-Oncogenes**