Ch. 5 Key Terms Flashcards
photosynthesis
energy from the sun enters an ecosystem when organisms use sunlight to make sugar
consumer
gets energy by eating producers or other consumers
ecological succession
gradual process of change and replacement of some or all of the species in a community.
decomposer
consumers that get their food by breaking down organic matter from dead organisms
cellular respiration
the process of breaking down carbohydrates to yield energy.
food chain
the path in which energy is transferred from one organism to the next as each organism eats another organism.
food web
includes more organisms and shows the feeding relationships between organisms that are possible in an ecosystem.
trophic level
each step through which energy is transferred in a food chain
carbon cycle
process by which carbon is cycled between the atmosphere, land, water, and organisms.
nitrogen-fixing bacteria
only a few species of bacteria can fix atmospheric nitrogen into a useful form called ammonia.
nitrogen cycle
a process by which nitrogen in cycled between the atmosphere, land, water, and organisms
phosphorus cycle
movement of phosphorus from the environment to organisms and then back to the environment
Producer
an organism that makes its own food
primary succession
succession can occur in areas that did not support life
secondary succession
occurs in areas where an ecosystem has previously existed
