The bite of an infected _______ causes sleeping sickness.

Options

A. Anopheles mosquito
B. fly
C. tsetse fly
D. Culex

Answer

To answer the question, "The bite of an infected _______ causes sleeping sickness," we need to identify the correct vector responsible for transmitting the disease.

### Step-by-Step Solution:

1. **Identify the Disease**: The question refers to "sleeping sickness." This disease is also known as African trypanosomiasis.

2. **Identify the Causative Organism**: The causative agent of sleeping sickness is a protozoan parasite called *Trypanosoma brucei*.

3. **Identify the Vector**: The disease is transmitted by a specific insect. In this case, the vector responsible for spreading sleeping sickness is the tsetse fly.

4. **Review Other Options**: The question provides other options such as "anaphylis mosquito" and "culex."
- The anaphylis mosquito is known for transmitting malaria, not sleeping sickness.
- Culex mosquitoes are known for transmitting diseases like West Nile virus and filariasis, but not sleeping sickness.

5. **Conclusion**: Based on the information, the correct answer to fill in the blank is "tsetse fly."

### Final Answer:
The bite of an infected **tsetse fly** causes sleeping sickness.

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