The competitive exclusion principle experiment involved species of .........

Options

A. Chlorella
B. Paramoecium
C. Microystis
D. Finches

Answer

To solve the question regarding which species was involved in the competitive exclusion principle experiment, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Competitive Exclusion Principle**:
- The competitive exclusion principle states that two species competing for the same resources cannot coexist indefinitely. One species will outcompete the other, leading to the exclusion of the inferior competitor.

2. **Identifying the Scientist**:
- The principle was formulated by the scientist G.F. Gause, who conducted experiments to demonstrate this concept.

3. **Reviewing the Options**:
- The options provided in the question are:
A. Chlorella
B. Paramecium
C. Microcystis
D. Fidgis

4. **Recalling the Experiment**:
- Gause conducted experiments using two species of Paramecium: Paramecium Aurelia and Paramecium Caudatum. He observed their growth under conditions where they competed for the same resources.

5. **Analyzing the Results**:
- In the experiment, when both species were grown together, Paramecium Aurelia was able to gather more food and thrive, while Paramecium Caudatum could not compete effectively and eventually died out.

6. **Conclusion**:
- Based on Gause's experiment, the species involved in demonstrating the competitive exclusion principle is **B. Paramecium**.

### Final Answer:
**B. Paramecium**

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