chapter five: key terms Flashcards
photosynthesis
the process by which plants, algae, and some bacteria use sunlight carbon dioxide, and water to produce carbohydrates and oxygen
producer
an organism that can make organic molecules from inorganic molecules; a photosynthetic or a chemosynthetic autotroph that serves as a basic food source in an ecosystem
consumer
an organism that eats other organisms or organic matter instead of producing its own nutrients or obtaining nutrients from other inorganic sources
decomposer
an organism that feeds by breaking down organic matter from dead organisms; examples including bacteria and fungi
cellular respiration
the process by which cells produce energy from carbohydrates; atmospheric oxygen combines with glucose to form water or carbon dioxide
food chain
the pathway of energy transfer through various stages as a result of the feeding patterns of a series of organisms
food web
a diagram that shows the feeding relationship between organisms in an ecosystem
trophic level
one of the steps in a food chain or food pyramid; examples include producers and primary, secondary, and tertiary consumers
carbon cycle
the movement of carbon from the nonliving environment into the living things and back
nitrogen-fixing bacteria
bacteria that convert atmospheric nitrogen into ammonia
nitrogen cycle
the process in which nitrogen circulates among the air, soil, plants, water, and animals in an ecosystem
phosphorus cycle
the cyclic movement of phosphorus in different chemical forms from the environment to organisms and then back to the environment
ecological succession
the gradual process of change and replacement in a community
primary succession
succession that begins in an area that previously did not support life
secondary succession
the process by which one community replaces another community that has been partially or totally destroyed
