Final answer:
Black bears get their energy from the food they consume, such as berries and fish. This food contains energy that originates from the sun, captured through photosynthesis by plants, which are then consumed directly or indirectly by the bear.
Step-by-step explanation:
All living things, including black bears, ultimately derive their energy from the sun. This process begins with producers like plants, algae, and certain bacteria that harness sunlight through photosynthesis to create organic molecules such as glucose. These producers serve as the foundational energy sources for all other organisms in an ecosystem.
Herbivores, or plant-eating animals, consume producers and absorb their stored energy. Carnivores, which include black bears when they eat other animals, then obtain energy by consuming herbivores or other carnivores. Energy is transferred through the food chain, but it originates from the sun's energy captured by producers through photosynthesis.
Therefore, when a black bear eats berries or fish, it is accessing energy that has passed through various levels of the food web but initially came from the sun. This energy flow is critical for all metabolic pathways in living organisms, which require energy to perform vital functions and maintain life.