Brainlag PlusTrophic levels, drawing pyramids of biomass to scale, why biomass is lost at each step, and calculating the efficiency of transfer (Biology only).
Trophic levels and pyramids
Level 1 is the producers, level 2 the primary consumers (herbivores), level 3 secondary consumers, level 4 tertiary consumers.
Apex predators are at the top. Decomposers break down dead material from every level.
A pyramid of biomass has one bar per level, its width in proportion to the dry biomass. Only about 1% of the light reaching producers is used in photosynthesis, and each level has less biomass than the one below.
- Producers 1500 g/m² drawn 15 cm wide: 1 g/m² = 0.01 cm
- Herbivores 240 g/m²: 240 × 0.01 = 2.4 cm
- Carnivores 30 g/m²: 0.3 cm
The rest of this lesson and its 11 practice questions are in Plus.
Screen 1 of 3, free to read.
- 11 exam-style questions, marked as you go, each with a worked solution
- Anything you get wrong is saved to your flashcards