Which one is true?

Options

A. Herbivores and plants appear to be more adversely affected by competition than carnivores
B. Carnivores appear to be more adversely affected by competition than herbivores
C. Herbivores, plants and carnivores are equally affected by competition.
D. Herbivores and carnivores are affected but not plants due to competition.

Answer

To determine which statement is true regarding the effects of competition on herbivores, plants, and carnivores, we can analyze the provided options step by step.

### Step-by-Step Solution:

1. **Understanding Competition**:
- Competition occurs when two or more species vie for the same limited resources, such as food, space, or light. This can lead to negative effects on the fitness of the competing species.

2. **Analyzing the Options**:
- **Option 1**: "Herbivores and plants appear to be more adversely affected by competition than carnivores."
- **Option 2**: "Carnivores appear to be more adversely affected by competition than herbivores."
- **Option 3**: "Herbivores, plants, and carnivores are equally affected by competition."
- **Option 4**: "Herbivores and carnivores are affected but not plants due to competition."

3. **Evaluating Each Option**:
- **Option 1**: This statement suggests that herbivores (which rely solely on plants for food) and plants (which compete for sunlight and nutrients) are more adversely affected by competition. This is reasonable because herbivores have a single food source, making them more vulnerable to competition with each other and with plants.
- **Option 2**: This statement implies that carnivores are more adversely affected than herbivores. However, carnivores typically have multiple food sources, which makes them less susceptible to competition than herbivores.
- **Option 3**: This suggests that all three groups are equally affected. However, given the reliance of herbivores on plants, this is not accurate.
- **Option 4**: This implies that plants are not affected by competition, which is incorrect as plants also compete for resources.

4. **Conclusion**:
- After evaluating the options, we find that **Option 1** is the most accurate statement. Herbivores and plants are indeed more adversely affected by competition than carnivores, due to their limited food sources and the nature of their interactions.

### Final Answer:
**Option 1 is true: Herbivores and plants appear to be more adversely affected by competition than carnivores.**