Name the method by which Spirogyra reproduces under favourable conditions. Is this method sexual or asexual ?

Explanation

**Step-by-Step Solution:**

1. **Identify the Organism**: The question asks about Spirogyra, which is a genus of green algae commonly found in freshwater environments.

2. **Determine the Method of Reproduction**: Under favorable conditions, Spirogyra reproduces through a method known as fragmentation.

3. **Explain Fragmentation**: Fragmentation is a type of asexual reproduction where the organism breaks into smaller pieces or fragments. Each of these fragments can grow into a new individual.

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