Energy Transfer - Energy and Ecosystems Flashcards
what is a producer?
a photosynthetic organism that manufactures organic substances using the sun’s energy
what is a consumer?
An organism that feeds on another organism
what is a trophic level?
a stage in a food chain
what are saprobionts?
organisms that break down the complex material in dead organisms into simple ones
what is biomass?
the total mass of living material in a specific area at a given time
what is a food web?
a series of linked food chains
what is a food chain?
a linear representation of the feeding relationship in an ecosystem
what is the ultimate source of energy in all ecosystems?
sunlight
how is sunlight conserved in plants?
as chemical energy
what do most plants use sunlight for?
making organic substances, usually sugars
what are the two forms of biomass?
fresh mass
dry mass
what is fresh mass?
all of the biomass of an organism
what is dry mass?
the biomass of an organism when all the water has been removed
what is an advantage of using fresh mass?
it is easy to access
what is a disadvantage of using fresh mass?
different organisms have varying amounts of water so not representative of the amount of other biological molecules present
what is an advantage of using dry mass?
it is more reliable
what are the disadvantages of using dry mass?
time consuming
organisms have to be killed
what are the units for biomass?
dry mass per given area
eg kg m-2