Which of the following shows biological antagonism or allelopathy?

Options

A. Amensalism
B. Proto-cooperation
C. Competition
D. Parasitism

Answer

To determine which of the options shows biological antagonism or allelopathy, we can follow these steps:

### Step 1: Understand Biological Antagonism and Allelopathy
Biological antagonism refers to the interaction between two species where one species is harmed while the other remains unaffected. Allelopathy is a specific type of biological antagonism observed primarily in plants, where one organism produces chemicals that inhibit the growth of another organism.

### Step 2: Identify Key Characteristics
- In biological antagonism, one species is harmed, and the other is unaffected.
- In allelopathy, the chemicals produced by one organism affect the growth of another organism.

### Step 3: Analyze the Options
We need to evaluate the provided options based on the definitions:
1. **Emensalism**: This is when one species is harmed while the other remains unaffected, which aligns with biological antagonism.
2. **Proto-cooperation**: This is a mutualistic relationship where both species benefit from each other, which does not fit.
3. **Competition**: This involves two species competing for resources, where neither is necessarily harmed, thus not fitting the criteria.
4. **Parasitism**: In this case, one species benefits at the expense of another, which does not align with the definition of biological antagonism where one remains unaffected.

### Step 4: Conclusion
Based on the analysis, the correct answer is **Emensalism**, as it shows a similar interaction to biological antagonism and allelopathy.

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