In the life cycle of Wuchereria , third and fourth moults of microfilaria take place in

Options

A. Lymph vessels of man
B. Salivary glands of mosquito
C. Thoracic muscles of mosquito
D. Stomach of mosquito

Answer

To answer the question regarding where the third and fourth moults of microfilaria occur in the life cycle of Wuchereria, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Life Cycle**: Wuchereria is a parasitic filarial worm that has a complex life cycle involving both humans and mosquitoes. The microfilariae are the larval stage of the worm.

2. **Role of Mosquitoes**: The primary vectors for Wuchereria are mosquitoes, specifically species like Culex, Anopheles, and Aedes. These mosquitoes play a crucial role in the transmission of the parasite.

3. **Development in Mosquito**: When the mosquito takes a blood meal, it ingests microfilariae. Inside the mosquito, the microfilariae lose their sheath and migrate to the thoracic muscles.

4. **Moulting Process**: In the thoracic muscles of the mosquito, the microfilariae undergo two moults (the second and third stages of development). This process is essential for them to develop into the infective stage.

5. **Migration to the Labium**: After the moulting in the thoracic muscles, the microfilariae migrate to the labium of the mosquito, which is the part that bites and transmits the larvae to a human host.

6. **Infection of Humans**: When the mosquito bites a healthy person, the infective larvae enter the human body, where they migrate to the lymphatic system.

7. **Final Moults in Humans**: The third and fourth moults of microfilariae occur in the lymphatic vessels of humans, where they develop into adult worms.

### Conclusion:
The third and fourth moults of microfilaria in the life cycle of Wuchereria take place in the lymphatic vessels of humans.

### Answer:
**Lymphatic vessels of men.**

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