Some basic ESS info:

1. What is a system:
   A set of components that act on a theoretically predictable manner. It has inputs and outputs.
2. Examples of ecosystems:
   Tundra, taiga, tropical rainforest, decidious rainforest, coniferous rainforest, chaparral, savanna, and desert.
3. Describe what are trophic levels:
   Trophic levels are the hierarchical level that a species occupies in the ecosystem.
   Ex.
   Grass (Producer) - Mice (1st consumer) - Bacteria (Decomposer)
4. Write about a particular ecosystem including mass and energy flows:
   In a grassland for example, energy is first produced by the grasses and herbs that inhabit the region. These are then eaten by mice, grasshoppers, and other small predators that are called primary consumers. These consumers are then eaten by secondary consumers as birds which are then eaten by teartiary consumers such as eagles and owls. In between each consuption, some energy is lost as heat and we must also count out that energy disposed as waste.