7.4.1 - Trophic Levels

What does a food chain show?

It describes the feeding relationships between organisms and the resultant stages of biomass transfer.

What are trophic levels?

The stages in a food chain.

How are trophic levels represented?

By numbers, starting from 1. After 1, trophic levels are numbered according to how far along the organism is in the food chain.

What is trophic level 1?

Plants and algae which make their own food (through photosynthesis) - called producers.

What is trophic level 2?

Herbivores which eat producers - called primary consumers.

What is trophic level 3?

Carnivores that eat herbivores - called secondary consumers.

What is trophic level 4?

Carnivores that eat other carnivores - called tertiary consumers.

What is an apex predator?

A carnivore with no predators.

How do decomposers break down dead matter?

• Decomposers release enzymes which catalyze the breakdown of dead material into smaller molecules.

• Soluble small food molecules then diffuse into the microorganisms.