Biology Regents Practice Exam

Which organism is an example of a primary producer in an ecosystem?

1. Fungi

2. Plants

3. Herbivores

4. Carnivores

The correct answer is: Plants

Primary producers are organisms that can create their own energy through the process of photosynthesis or chemosynthesis, forming the foundation of the food chain in an ecosystem. Plants are a prime example of primary producers because they utilize sunlight, carbon dioxide, and water to produce glucose and oxygen through photosynthesis. This ability to convert inorganic substances into organic matter enables them to serve as a crucial energy source for other organisms within the ecosystem. Fungi, while important decomposers, do not produce their own energy from sunlight; instead, they break down organic material. Herbivores consume primary producers but do not produce energy themselves. Similarly, carnivores feed on herbivores or other carnivores and rely on the energy originally captured by primary producers. Thus, plants are distinct as primary producers that initiate the flow of energy in ecological networks.