What is the study of the relationships of organisms and their environment called? ecology What is a group of organisms and their environment called? ecosystem In an ecosystem, what are living things that affect other organisms called? biotic factors In an ecosystem, what are nonliving things that affect organisms called? abiotic factors What is the place an organism lives called? habitat What is the term for the way a particular organism fits into its ecosystem? niche What is the number of organisms of a particular type in a particular region called? population What is a group of ecological populations called? community What does the word "autotroph" mean? self feeding What does the word "heterotroph" mean? feeding on others What is another word for autotroph? producer What is another word for heterotroph? consumer What is an animal that eats only plants called? herbivore What is an animal that eats only other animals called? carnivore What is an animal that eats both animals and plants called? omnivore What is an animal that eats decomposed plants and animals called? detritovore What is a series of organisms, each of which consumes the one before it, called? food chain What is a cross-connecting and branching system of food chains called? food web What is the relatively thin shell around Earth that supports life called? biosphere What is the position that an organism occupies in a food chain called? trophic level What is the maximum population that a given habitat can support called? carrying capacity What is a variable that, when changed, changes the maximum size of a given population called? limiting factor What is a factor whose effects change with the population size in a given area called? density-dependent Is the climate a density-dependent or density-independent factor? density-independent What capital letter does the shape of an exponential growth curve most resemble? J What capital letter does the shape of a logistic growth curve most resemble? S What percentage of useful energy is typically lost between two adjacent trophic levels? 90 What is the term for the idea that energy can be neither created nor destroyed, only transformed? conservation of energy What is the term for the idea that matter can be neither created nor destroyed, only moved around? conservation of mass What does the word "symbiosis" mean? living together In what form of symbiosis does one species benefit while the other is mostly unaffected? commensalism In what form of symbiosis does one species benefit while the other is harmed? parasitism In what form of symbiosis do both species benefit? mutualism Is predation usually considered a form of symbiosis? no What is the term for a "major ecological community type"? biome What are "jungle", "grassland", "wetland", "deciduous forest", "tundra", "taiga", and "desert" examples of? biomes In what process do a series of species colonize a new or disturbed environment? succession What kind of succession occurs in a mostly lifeless environment? primary What kind of succession occurs after a disturbance in an established ecosystem? secondary What is the term for a species that first colonizes a lifeless environment? pioneer What mutualistic association of a fungus and an alga colonizes islands recently formed by lava flows? lichen What are the major processes of the water cycle? evaporation, condensation, precipitation, and runoff What process primarily removes carbon from the atmosphere? photosynthesis What process primarily puts carbon back into the atmosphere? cellular respiration In the nitrogen cycle, what process primarily removes nitrogen from the atmosphere? fixation What kind of organisms do nitrogen fixation? bacteria Where do nitrogen-fixing bacteria live? soil On what parts of plants do some nitrogen-fixing bacteria live? roots How does phosphorus enter the ecosystem? weathering of phosphate rocks Where does phosphorus in the ecosystem eventually end up? ocean floor What does the word "tropism" mean in Greek? turning What form of tropism causes a plant to grow toward light? phototropism What form of tropism causes a plant's roots to grow down while its shoots grow up? gravitropism What form of tropism causes a vine to wrap around a support? thigmotropism What form of tropism causes roots to grow toward water? hydrotropism