Biology Regents Practice Exam

Which sequence illustrates the flow of energy through an ecosystem?

1. Sunlight → Plant → Wolf → Rabbit

2. Plant → Sunlight → Rabbit → Wolf

3. Sunlight → Plant → Rabbit → Wolf

4. wWolf → Rabbit → Plant → Sunlight

The correct answer is: Sunlight → Plant → Rabbit → Wolf

The sequence that illustrates the flow of energy through an ecosystem correctly identifies the source of energy and the organisms that utilize it. In this case, the correct sequence begins with sunlight, which is the primary energy source for nearly all ecosystems. Plants, through the process of photosynthesis, convert sunlight into chemical energy, forming the base of the food chain as producers. Following the plants, rabbits, as herbivores, consume the plants to obtain energy. This transfer of energy from plants to rabbits represents primary consumption. Subsequently, wolves, which are carnivores, consume the rabbits, thereby acquiring energy from the second level of consumption. This sequence effectively demonstrates the energy flow: sunlight as the initial energy source, followed by the plants that harness it, then the herbivores that consume the plants, and finally the carnivores that feed on those herbivores. Such a flow is critical for understanding the interdependence of organisms within an ecosystem, as energy moves through various trophic levels from producers to consumers.