Correct Option: C. Sleeping Sickness Detailed Explanation: The tsetse fly, scientifically known as Glossina, is a significant vector in the transmission of a disease called sleeping sickness, or African trypanosomiasis. This disease is caused by parasitic protozoa of the genus Trypanosoma, specifically Trypanosoma brucei gambiense and Trypanosoma brucei rhodesiense.

1. Life Cycle of the Tsetse Fly:
2. The tsetse fly becomes infected with the Trypanosoma parasites when it feeds on the blood of an infected host, typically humans or animals.
3. The parasites multiply within the fly and can be transmitted to a new host when the fly bites again.
4. Symptoms of Sleeping Sickness:
5. The disease progresses in two stages. The first stage includes fever, headaches, joint pains, and itching.
6. The second stage affects the central nervous system, leading to confusion, sensory disturbances, and sleep cycle disruptions, hence the name "sleeping sickness."
7. Geographical Distribution:
8. Sleeping sickness is primarily found in sub-Saharan Africa, where the tsetse fly is endemic. This makes it a significant public health concern in these regions.

Why Other Options Are Incorrect:

• A. River Blindness:
• River blindness, or onchocerciasis, is caused by the parasitic worm Onchocerca volvulus, which is transmitted by blackflies, not tsetse flies. Therefore, this option is incorrect.
• B. Malaria:
• Malaria is caused by Plasmodium parasites and is transmitted by Anopheles mosquitoes. The tsetse fly does not play a role in the transmission of malaria, making this option incorrect.
• D. Leprosy:
• Leprosy, or Hansen's disease, is caused by the bacterium Mycobacterium leprae and is primarily transmitted through prolonged close contact with an infected person. It is not associated with any insect vector, including the tsetse fly, thus this option is also incorrect.

Summary of Key Points:

• The tsetse fly is a vector for sleeping sickness, caused by Trypanosoma parasites.
• Sleeping sickness has two stages, affecting both the blood and the central nervous system.
• Other diseases listed (river blindness, malaria, leprosy) are transmitted by different vectors or mechanisms, not the tsetse fly.
• Understanding the specific vectors and diseases is crucial for effective disease prevention and control strategies.

This thorough understanding of the tsetse fly's role in disease transmission is essential for anyone studying biology, particularly in the context of public health and disease ecology.