Biology STAAR (State of Texas Assessments of Academic Readiness) Practice Test

What is the primary benefit of mutualism in an ecosystem?

1. Increased competition for resources

2. One species takes advantage of another

3. Mutual dependence and support

4. Reduction of predators

The correct answer is: Mutual dependence and support

The primary benefit of mutualism in an ecosystem is mutual dependence and support between different species. In mutualistic relationships, both organisms involved gain benefits that enhance their survival, reproduction, or overall fitness. For example, bees pollinate flowers while feeding on nectar, benefiting the plants by facilitating reproduction and providing the bees with food. This interdependence helps maintain the balance within ecosystems, as it fosters healthy interactions that can lead to greater biodiversity and stability. In contrast, increased competition for resources generally refers to situations where organisms vie for limited supplies, which can have negative impacts on one or more species involved. The notion of one species taking advantage of another typically describes parasitism or predation rather than mutualism. Reduction of predators, while beneficial in some contexts, is not a direct benefit associated with mutualistic interactions, which focus on the cooperative relationships between species. Thus, the essence of mutualism lies in the supportive and reciprocal interactions that promote the well-being of the organisms involved.