How is cocoon produced in the earthworm?

Explanation

**Step-by-Step Solution:**

1. **Understanding Earthworms**: Earthworms are segmented organisms with a tube-like shape. They are also known as bisexual organisms, meaning they possess both male and female reproductive organs.

2. **Identifying the Clitellum**: The clitellum is a thickened, glandular, non-segmented section of the earthworm's body, located towards the anterior end. It is crucial for reproduction and is visible only when the worm is sexually mature.

3. **Secretion of Viscid Sac**: The clitellum secretes a viscous fluid that forms a sac. This sac is essential for the reproduction process as it serves as a cocoon for the eggs.

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