Download Energy in an Ecosystem Summary Notes

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Summary Notes
National 5 – Life on Earth- Energy in an Ecosystem
Only about 10% of available energy is passed on to the next level of a food chain
Energy is lost from a food chain through:
movement
heat
undigested material (eventually decomposed)
A pyramid of numbers shows the total number of organisms in each population in
the food chain. Generally numbers decrease further up the pyramid but
occasionally there can be an irregular shape
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A pyramid of biomass shows the total mass of organisms in each population in the
food chain. It is measured in g/m2
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A pyramid of energy shows the total energy available from each population of the
food chain over a given period of time. It is measured in Joules/m-2/year
Interspecific competition occurs between organisms of different species when
competing for similar resources
Intraspecific competition occurs between organisms of the same species when
they compete for the same resources
Nitrogen is an essential element in manufacturing protein plants and animals
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Nitrates can be added to the soil as fertiliser in order to improve yield
Repeating an experiment improves the reliability of its results
Changing only one variable in an experiment improves the validity of its results