Theory question 206
The Ecosystem(a) Distinguish between an ecosystem and a food chain
(b) Explain the interdependence of the biotic and abiotic components of the environment
Show the model answer
(a) Ecosystem: a community of living organisms interacting with each other and with their non-living environment in a given area (e.g. a pond, a forest). Food chain: the sequence of feeding relationships through which energy passes from producers to consumers, e.g. grass → grasshopper → toad → hawk; it is only one part of an ecosystem
(b) Plants (biotic) need sunlight, water, carbon dioxide and soil nutrients (abiotic) for photosynthesis and growth; animals need oxygen, water and shelter; plants release oxygen and use CO₂, animals release CO₂ in respiration; decomposers return nutrients to the soil; vegetation protects soil from erosion and adds humus; climate controls which organisms live in an area while plants modify the micro-climate
Show the exchange going both ways in (b).