In Ascaris 3rd moulting takes place in

Options

A. (a) intestine
B. (b) lung
C. (c) liver
D. (d) egg

Answer

**Step-by-Step Solution:**

1. **Understanding Ascaris**: Ascaris is a parasitic roundworm belonging to the phylum Nematoda. It primarily infects the intestines of its host, usually humans.

2. **Life Cycle of Ascaris**: The life cycle of Ascaris involves several stages, including the larval stage and the adult stage. The larvae develop in the soil and are transmitted to humans through contaminated food or soil.

3. **Stages of Development**:
- The first stage is the **larval stage**, also known as the **rhabditoid stage**, which occurs in the soil.
- After ingestion, the larvae travel through the intestines to the bloodstream and then to the lungs.

4. **Molting Process**: Molting refers to the shedding of the old cuticle (skin) to allow for growth. Ascaris undergoes four molts during its life cycle:
- The **first molting** occurs in the larval stage in the soil.
- The **second molting** occurs when the larvae are in the intestines after being ingested.
- The **third molting** occurs in the lungs, where the larvae migrate after leaving the intestines.
- The **fourth molting** occurs in the intestines when they develop into adult worms.

5. **Identifying the Correct Answer**: The question specifically asks when the third molting occurs. Based on the life cycle of Ascaris, the third molting takes place in the lungs.

6. **Final Answer**: Therefore, the correct answer to the question is **B) Lungs**.

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