Mechanism of organic evolution proposed by Hugo de Vries is based upon:

Options

A. Mutation
B. Variation
C. Adaptation
D. Reproduction

Answer

**Step-by-Step Solution:**

1. **Identify the Contributor**: The question asks about the mechanism of organic evolution proposed by Hugo de Vries. It is important to recognize who Hugo de Vries is and his contributions to evolutionary biology.

2. **Understand the Concept of Organic Evolution**: Organic evolution refers to the gradual development of life forms from simple to more complex organisms over time. Various mechanisms have been proposed to explain how this process occurs.

3. **Focus on Hugo de Vries' Proposal**: Hugo de Vries is known for his work on mutation theory. He proposed that mutations, which are sudden and heritable changes in an organism's genetic material, play a crucial role in the process of evolution.

4. **Define Mutation**: A mutation is a change in the DNA sequence that can lead to new traits in an organism. These mutations can be beneficial, harmful, or neutral, and they contribute to the genetic variation within a population.

5. **Conclusion**: Based on the above points, the mechanism of organic evolution proposed by Hugo de Vries is primarily based on the concept of mutation.

**Final Answer**: The mechanism of organic evolution proposed by Hugo de Vries is based upon mutation.

---