What are the three trophic levels?
Trophic levels can be represented by numbers, starting at level 1 with plants. [ Further trophic levels are numbered subsequently according to how far the organism is along the food chain.
Level 1: Plants and algae make their own food and are called primary producers.
Level 2: Herbivores eat plants and are called primary consumers.
Level 3: Carnivores which eat herbivores are called secondary consumers.
Level 4: Carnivores which eat other carnivores are called tertiary consumers.
Level 5: Apex predators which have no predators are at the top of the food chain. ]