In which of the following interaction both partners are adversely affected ?

Options

A. Competition
B. Predation
C. Parasitism
D. Mutualism

Answer

To determine which interaction adversely affects both partners, we can analyze the different types of ecological interactions.

### Step-by-Step Solution:

1. **Understanding the Types of Interactions**:
- There are various types of interactions between organisms in an ecosystem, including competition, predation, parasitism, and mutualism.

2. **Analyzing Competition**:
- In competition, two organisms compete for the same resources (like food, water, or territory). This competition can lead to a loss of energy and resources for both organisms involved. Therefore, both partners can be adversely affected.

3. **Analyzing Predation**:
- In predation, one organism (the predator) benefits by consuming another organism (the prey). If the predator successfully catches the prey, the predator benefits, while the prey is adversely affected (it dies). If the prey escapes, it benefits, but the predator may suffer from starvation. Hence, in predation, only one partner is adversely affected at a time.

4. **Analyzing Parasitism**:
- In parasitism, one organism (the parasite) benefits at the expense of another organism (the host). The parasite thrives on the host, which is adversely affected. Thus, in this interaction, only the host is negatively impacted.

5. **Analyzing Mutualism**:
- In mutualism, both organisms benefit from the interaction. For example, bees pollinate flowers while obtaining nectar. Therefore, neither partner is adversely affected in this interaction.

6. **Conclusion**:
- From the analysis, the only interaction where both partners are adversely affected is **competition**. Therefore, the correct answer to the question is competition.

### Final Answer:
**Competition** is the interaction in which both partners are adversely affected.

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