Name the scientist who proposed mutation theory. On which plant, he worked upon?

Explanation

**Step-by-Step Solution:**

1. **Identify the Scientist**: The scientist who proposed the mutation theory is Hugo de Vries. He is known for his work in the field of genetics and evolution.

2. **Identify the Plant**: The plant on which Hugo de Vries conducted his experiments is known scientifically as Oenothera lamarckiana, commonly referred to as the Evening Primrose.

3. **Explanation of the Mutation Theory**: Hugo de Vries suggested that mutations are sudden changes in the genetic material (DNA) that can lead to variations in traits. He observed that these variations could be inherited from one generation to the next.

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