AP®︎ Biology: Topic 8.2 Flashcards
Master key terms and definitions for Topic 8.2 of AP Biology – Energy Flow Through Ecosystems to help you prep for quizzes and the AP exam.
Energy Flow Through Ecosystems
Energy enters as sunlight or chemicals, moves through trophic levels, and is lost as heat.
Energy enters as sunlight or chemicals, moves through trophic levels, and is lost as heat.
Feeding positions in a food chain or web based on how organisms obtain energy.
Organisms that make organic molecules using energy from sunlight or inorganic chemicals.
Organisms that obtain energy and carbon by eating other organisms or organic matter.
Primary eat producers; secondary eat primary consumers; tertiary eat secondary; quaternary are top predators.
Decomposers chemically break down dead matter; scavengers eat carcasses; omnivores eat plants and animals.
A linear feeding path versus an interconnected network of feeding relationships in an ecosystem.
A diagram showing decreasing available energy and usually decreasing biomass at higher feeding levels.
Only about one-tenth of energy at one trophic level becomes biomass in the next.
The total mass of living organic matter in a given area or trophic level.
The rate at which autotrophs convert environmental energy into organic compounds.
One uses sunlight to build organic molecules; the other uses energy from inorganic chemical reactions.
One maintains body temperature with metabolic heat; the other relies mainly on external heat sources.
Temperature control by changing behavior, such as basking, seeking shade, or clustering together.
Surplus energy supports storage, growth, and reproduction; deficit causes mass loss and eventual death.
Patterns of growth, energy use, and reproduction shaped by environmental conditions and resource availability.
Breeding timed so offspring develop when environmental conditions and resources are most favorable.
Plants that grow vegetatively one year, then flower, reproduce, and die the next.
A temporary pause in development or reproduction during unfavorable conditions to conserve energy.
Low energy often favors asexual reproduction; abundant energy can support costlier sexual reproduction.
Population is one species, community is interacting species, ecosystem includes abiotic factors, biome is a major region.
Pathways that move matter between organisms and abiotic reservoirs while conserving atoms.
Nonliving storage sites like air, water, and rocks versus living organisms that temporarily store matter.
Carbon moves through photosynthesis, respiration, decomposition, and combustion between organisms and the environment.
Fixation makes NH3/NH4+, assimilation builds biomass, ammonification returns NH4+, nitrification makes NO2-/NO3-, denitrification makes N2.
Weathering releases phosphate from rocks, organisms incorporate it, and decomposition returns it to soil and water.
More available energy can increase population size, while less energy reduces survival and reproduction.
Changes in producer energy capture or abundance alter all higher trophic levels above them.
Higher producer biomass supports more consumers, while producer declines shrink upper trophic levels.
The number of trophic transfers in a feeding pathway, limited by energy loss at each step.
Water moves among oceans, atmosphere, surface water, and organisms by evaporation, condensation, precipitation, and transpiration.
Nitrogen cycles through atmosphere, soil, and organisms, with the atmosphere as the largest reservoir.
Cells break down organic molecules to release energy and return carbon dioxide to the environment.
