Each stage in a food chain is called a trophic level, and the arrows represent the flow of
energy and matter through the food chain.
- Food chains always start with photosynthetic producers (plants, algae, plankton and photosynthetic bacteria) because, uniquely, producers are able to extract both energy and matter from the abiotic environment.
- All other living organisms get both their energy and matter by eating other organisms. All living organisms need energy and matter from their environment.
- Matter is needed to make new cells (growth) and to create new organisms (reproduction), while energy is needed to drive all the chemical and physical processes of life, such as biosynthesis, active transport and movement.
Deep water ecosystems have few producers (since there is little light), so the main food source for consumers is detritus washed down from rivers.
The top of a food chain is often not a top consumer, but rather scavengers or parasites feeding on them.
Comments
No comments have yet been made