TDF gene is a :-

Options

A. A gene present on X-chromosome
B. A segment of RNA
C. A proteinaceous factor
D. A gene present on Y-chromosome

Answer

### Step-by-Step Solution:

1. **Understanding the TDF Gene**:
- TDF stands for Testes Determining Factor. It is a crucial gene involved in the development of male characteristics.

2. **Location of the TDF Gene**:
- The TDF gene is located on the Y chromosome. This is significant because the Y chromosome is typically present only in males.

3. **Function of the TDF Gene**:
- The primary function of the TDF gene is to initiate the development of testes, which are the primary male sex organs. This process is essential for male sexual differentiation.

4. **Exclusion of Other Options**:
- The question provides several options:
- Gene present on X chromosome
- Segment of RNA
- Proteinaceous factor
- Gene present on Y chromosome
- Since the TDF gene is specifically located on the Y chromosome, the other options can be ruled out:
- It is not present on the X chromosome.
- It is not merely a segment of RNA or a proteinaceous factor; it is a gene that encodes for a specific function.

5. **Conclusion**:
- Therefore, the correct answer is that the TDF gene is a gene present on the Y chromosome.

### Final Answer:
The TDF gene is a gene present on the Y chromosome.

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