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13 terms

Global ecology 3

Bio
STUDY
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Autotrophs
Produce their own food from solar energy by photosynthesis; transform solar energy into chemical energy; primary producer
Ecologists classify organisms
By how they obtain their energy
Heterotrophs
Consume other organisms (consumers); Get energy from primary producers; carnivores, herbivores
Decomposers
Break down the dead; mostly fungi and bacteria
Detritivores
Eat detritis: partially decomposed matter in water or soil
Trophic structure
A pattern of feeding relationships consisting of different levels
Food chain
Sequence of food transfer up the trophic levels
Producers
Support all other trophic levels; autotrophs; plants on land, cyanobacteria in water
Consumers
Heterotrophs: Primary, secondary, tertiary, quaternary

Detritivores and decomposers derive energy from dead materials and wastes
Food web
Collection of all food chains in an ecosystem
Components of ecosystems
Energy flow: passage of energy through the ecosystem
Chemical cycling: Transfer of materials within the ecosystem
Energy flow and nutrient cycling
Nutrients cycle, but energy flows through a system
Trophic level
Composed of all the organisms that feed at a particular link in the food chain. 10% of energy is transferred from one trophic level to another. At each step, some usable energy is lost as heat.