Yes, you can definitely use case studies and real-life examples to explain the different disease control methods in your answers for Paper I of UPSC Zoology Optional subject. By incorporating case studies and real-life examples, you can provide concrete evidence and practical insights into the effectiveness of various disease control methods. This not only enhances the quality of your answers but also demonstrates your understanding of the subject matter.

Using case studies and real-life examples can be particularly beneficial in showcasing the application of disease control methods in different contexts and settings. It helps to illustrate how these methods have been successfully implemented and the impact they have had on disease prevention and control. Moreover, by referring to specific cases and examples, you can highlight the challenges encountered, the strategies employed, and the outcomes achieved.

Here is a suggested structure for your answer:

1. Introduction:
- Briefly introduce the importance of disease control and the need for effective methods.

2. Disease Control Method 1:
- Explain the first disease control method, such as vaccination or quarantine.
- Provide a case study or real-life example where this method was successfully implemented.
- Describe the specific context, the disease being targeted, and the outcomes achieved.

3. Disease Control Method 2:
- Explain the second disease control method, such as vector control or hygiene practices.
- Provide a case study or real-life example where this method was effectively applied.
- Highlight the specific measures taken, the challenges faced, and the impact on disease control.

4. Disease Control Method 3:
- Explain the third disease control method, such as surveillance or public health campaigns.
- Provide a case study or real-life example that demonstrates the effectiveness of this method.
- Discuss the strategies employed, the involvement of various stakeholders, and the results obtained.

5. Conclusion:
- Summarize the importance of using case studies and real-life examples to explain disease control methods.
- Emphasize the practical relevance and applicability of these methods in real-world scenarios.

By following this structure and incorporating relevant case studies and real-life examples, you can provide a comprehensive and well-supported answer to demonstrate your understanding of disease control methods in UPSC Zoology Optional Paper I.