IB ESS Topic 2

Biotic factors - Answer- the living organisms in an ecosystem abiotic factors - Answer- the non-living factors in an ecosystem trophic level - Answer- the position an organism occupies in a food chain as a result of its feeding habits food chain - Answer- a simple linear relationship which shows how energy is transferred between organisms as each consumes an organism from a lower trophic level food web - Answer- a group of interconnected food chains biomass - Answer- the mass of organic material in an organism or ecosystem producers - Answer- convert light energy and water, CO2 and minerals into new materials consumers - Answer- cannot make their own food and much eat other organisms to obtain energy Ecological pyramids - Answer- allow you to examine easily energy transfers and losses. they give an idea of what feeds on what and what organisms exist at the different trophic levels. they also help demonstrate that ecosystems are unified systems, and they are in balance pyramid of numbers - Answer- represents the number of organisms at each trophic level pyramid of biomass - Answer- represents the standing stock of each trophic level pyramid of productivity - Answer- represents the flow of energy through a trophic level species - Answer- a particular type of organism that can be interbreed and produce fertile offspring population - Answer- a group of one species living in a given area at the same time habitat - Answer- the environment where a species normally lives niche - Answer- how an organism makes a living community - Answer- a group of populations in a given area