Biology Regents Practice Exam

What characteristic is essential for a stable ecosystem?

1. A high number of predators

2. An interdependence of organisms

3. A lack of biodiversity

4. An increase in human interference

The correct answer is: An interdependence of organisms

The characteristic that is essential for a stable ecosystem is the interdependence of organisms. This concept refers to the relationships and interactions among various species, including plants, animals, and microorganisms within an ecosystem. Each organism plays a specific role, such as a producer, consumer, or decomposer, contributing to the overall balance and health of the ecosystem. Through interdependence, organisms rely on each other for food, shelter, pollination, seed dispersal, and nutrient cycling. This connectivity means that the disruption of one species can affect others, highlighting the importance of a balanced network of relationships. In stable ecosystems, these interdependent relationships can help buffer against environmental changes, allowing the ecosystem to recover from disturbances and maintain its functions. In contrast, options like a high number of predators, a lack of biodiversity, and an increase in human interference do not promote stability. For instance, while predators are crucial for controlling populations, an excessive number can lead to imbalances. A lack of biodiversity can make ecosystems more vulnerable to diseases and environmental changes, while increased human interference often leads to habitat destruction and pollution, further destabilizing ecosystems. Thus, interdependence stands out as a foundational element for ecosystem stability.