Ch. 5 Key Terms Flashcards
photosynthesis
when a plant uses sunlight to make sugar molecules
producer
organisms that make their own food by photosynthesis
consumer
organism that obtains its energy by feeding on other organisms
decomposer
organisms that break down food to yield energy
cellular respiration
process of breaking down food to yield energy
food chain
Series of levels in which organisms transfer energy by eating and being eaten
food web
Overlapping food chains
trophic level
each step in the transfer of energy, comes in the form of sugars which an organism breaks down for energy
carbon cycle
process by which carbon is cycled between the atmosphere, land, water, and organisms
nitrogen-fixing bacteria
organisms that can fix atmospheric nitrogen into chemical compounds
nitrogen cycle
process in which nitrogen is cycled between the atmosphere, bacteria, other organisms
phosphorus cycle
movement of phosphorous from the environment to organisms and then back
ecological succession
gradual process of change and replacement of the types of species in a community
primary succession
type of succession that occurs on a surface where no ecosystem existed before (rocks, sand, dunes)
secondary succession
more common type of succession, occurs on surface where ecosystems existed before
