13.1: Food chains and energy transfer Flashcards
Biomass
The total mass of living material in a specific area at a given time
Producer
Photosynthetic organisms that manufacture organic substances using: light energy, water, CO2 and mineral ions
Primary Consumer
Animals that directly eat producers
Secondary Consumer
Animals that eat primary consumers
Tertiary Consumer
Animals that eat secondary consumers
Consumers
Organisms that obtain their energy by feeding on other organisms (rather than directly using sunlight energy)
Predators
Usually secondary and tertiary consumers but also scavengers and parasites
Scavengers
An organism that consumes decaying biomass eg: meat or plant material
Parasites
An organism that obtains nourishment and shelter on another organism
(usually parasites benefit and the host does not)
Saprobiont
(decomposers)
Organisms that break down the complex materials in dead organisms into simple ones
Food chain
Feeding relationship and each stage in the chain is a trophic level
Food web
Very complex link of lots of food chains
Fresh mass
biomass
Easy access but presence of water makes it unreliable
Dry mass/ carbon
biomass
Overcomes (fresh mass) problem but means killing the organisms so only a small sample can be taken which may not be representative
Measuring biomass units
dry mass per given area in a given time
area: gm-2
volume: gm-3