Competition occurs when

Options

A. closely related species compete for same resources
B. unrelated species compete for same resources
C. both 1 and 2
D. natural resources are unlimited

Answer

### Step-by-Step Solution:

1. **Understanding Competition**:
- Competition occurs when organisms vie for the same limited resources in an environment. Resources can include food, water, space, and mates.

2. **Types of Competition**:
- There are two main types of competition:
- **Intraspecific Competition**: This occurs between individuals of the same species. For example, two dogs fighting over a single bone is an example of intraspecific competition.
- **Interspecific Competition**: This occurs between individuals of different species competing for the same resource. For example, a lion and a hyena competing for the same prey.

3. **Scarcity of Resources**:
- Competition intensifies when resources are scarce. When there is a limited supply of a resource, organisms must compete more fiercely for access to it.

4. **Interference Competition**:
- This is a specific type of competition where organisms directly interact with each other while competing for a resource. For example, if two animals fight over territory or food, this is considered interference competition.

5. **Analyzing the Options**:
- The question presents two options regarding competition:
- Option 1: Closely related species compete for the same resource (this can be true in the case of interspecific competition).
- Option 2: Unrelated species compete for the same resource (this is also true in interspecific competition).
- Both options describe scenarios where competition occurs.

6. **Conclusion**:
- Competition occurs when organisms (either of the same species or different species) compete for limited resources. It can manifest as intraspecific or interspecific competition, depending on whether the competing organisms are of the same species or different species.