Food Chains

Producers

Organisms that make their own food using energy from the sun or chemicals.

Consumers

Organisms that cannot make their own food and get energy by eating other organisms.

Primary consumers

Consumers that eat producers, such as rabbits that eat grass.

Secondary consumers

Consumers that eat primary consumers, such as snakes that eat rabbits.

Tertiary consumers

Consumers that eat secondary consumers, such as eagles that eat snakes.

Apex predators

Top of the food chain with no natural predators, such as lions or killer whales.

Photosynthesis

Process by which producers make their own food using energy from the sun.

Chemosynthesis

Process by which certain organisms make their own food using energy from chemicals.

Food chain

A sequence that shows how energy flows through an ecosystem, from producers to consumers.

Top-down control

When consumers in higher trophic levels affect organism abundance at lower trophic levels.

Bottom-up control

When abundance at higher trophic levels is limited by nutrients or food availability at lower levels.