AP®︎ Biology: Unit 8 Flashcards

The ability to detect and respond to internal or external environmental changes.

Behavioral responses change actions; physiological responses change internal body processes like hormones or enzymes.

A plant response to day length that helps time seasonal events like flowering.

Growth of a plant toward or away from a light source.

Taxis is directed movement toward or away from a stimulus; kinesis is random movement changing with stimulus intensity.

Nocturnal organisms are active at night; diurnal organisms are active during the day.

A rapid physiological stress response that prepares the body for immediate action.

Damage triggers chemical defenses and can signal nearby plants to activate protective responses.

Signals may be visual, audible, tactile, electrical, or chemical, each conveying information between organisms.

Behavioral displays or interactions used to attract mates and increase reproductive success.

Signals and behaviors between parents and young that promote care, feeding, and survival.

Signals used to locate, share, or coordinate access to food resources.

Signals used to establish social rank, defend space, and reduce direct conflict.

Innate behaviors are inherited; learned behaviors develop through experience and practice.

An organism's relative ability to survive and produce fertile offspring.

Group behaviors that improve protection, foraging, navigation, or hunting through coordinated action.

Large-group coordination in social organisms that supports defense, reproduction, or resource collection.

Signals that alert others to danger and trigger defensive or escape behaviors.

Natural selection favoring behaviors that help relatives survive and reproduce because they share genes.

Behavior in which individuals work together to improve survival, access to resources, or reproductive success.

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 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.

Changes in producer energy capture or abundance alter all higher trophic levels above them.

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.

Autotrophs that convert light or chemical energy into organic molecules, forming the base of food webs.

Energy availability helps determine producer biomass and the size of higher trophic levels; more producer biomass supports larger consumer populations, while reduced energy or producer decline shrinks upper trophic levels.

A group of individuals of the same species living in the same area.

Change in population size over time equals births minus deaths: dN/dt = B - D.

Rapid increase at a constant per capita rate under ideal, unlimited conditions, producing a J-shaped curve.

Population change equals maximum per capita growth rate times population size: dN/dt = rmaxN.

The highest possible per individual growth rate under ideal environmental conditions.

Environmental conditions that restrict population growth by reducing survival or reproduction.

The supply of food, water, oxygen, shelter, and other necessities in an environment.

The environment where organisms live, obtain resources, and reproduce.

An interaction in which one organism kills and eats another.

The spread of pathogens within a population that lowers survival or reproduction.

Long-term patterns of temperature, precipitation, and weather that affect habitats and resources.

Inherited traits that help organisms acquire and use resources in a specific environment.

A graph pattern showing rapid exponential increase when resources are unlimited.

Abiotic factors are nonliving physical and chemical conditions, while biotic factors are living organisms and interactions that influence survival, distribution, and ecosystem structure.

The number of individuals of a species per unit area or volume.

A condition where population size exceeds available resources, increasing competition, mortality, and stress.

The maximum population size an environment can sustainably support with available resources.

Population growth that slows as resources become limited and levels off near carrying capacity.

dN/dt = rmaxN(1 - N/K), relating growth rate to population size and carrying capacity.

dN/dt: population change over time; rmax: maximum per capita growth rate; N: population size; K: carrying capacity.

Exponential growth assumes unlimited resources; logistic growth slows and stabilizes as resources become limited.

Limiting factors either intensify with population density or affect populations regardless of density.

Competition and disease depend on crowding, while weather and disasters affect populations regardless of density.

All interacting populations of different species living in the same area.

The organization of species in a community based on composition and diversity.

The identity or list of species present in a community.

Calculated as 1 - Σ(n/N)^2 to estimate community diversity from richness and evenness.

Resource use differences that reduce competition and allow species to coexist.

Includes the number of species present and how evenly individuals are distributed.

A close interspecific relationship that benefits both, benefits one, or harms a host.

A minus-minus interaction in which organisms struggle for the same limited resources, reducing access for each competitor.

The variety of life in an ecosystem, including genetic and species differences.

Variation in alleles among individuals of the same species within a population.

The variety and relative abundance of different species in an ecosystem.

Ecosystems with few species or little variation are less able to resist and recover from change.

Multiple species perform similar ecological roles, providing backup if one declines.

A species with a disproportionately large effect on ecosystem structure relative to its abundance.

Removing a disproportionately influential species can trigger trophic changes and community breakdown.

Immediate changes include altered population sizes, resources, competition, and species interactions.

Over time, adaptation, reorganization, and new stable community structures may develop.

The abilities of an ecosystem to withstand disturbance and recover after environmental change.

A chain reaction across trophic levels in which changes in predator or prey populations indirectly alter other populations and ecosystem structure.

A heritable variation favored by selection because it increases fitness in a specific environment.

Mutations arise by chance, but selection nonrandomly increases beneficial variants and removes harmful ones.

The heterozygous genotype has higher fitness than either homozygous genotype in a given environment.

A nonnative organism that spreads in a new ecosystem and disrupts native populations or ecosystem processes.

Introduced species often expand rapidly because predators, parasites, or competitors are absent in the new habitat.

An introduced vine in the southeastern United States that rapidly overgrows and smothers native vegetation.

An invasive freshwater mollusk that clogs infrastructure and removes plankton from aquatic food webs.

Toxin concentration increases at higher trophic levels as predators consume contaminated prey.

Excess nutrients cause algal blooms whose decomposition depletes oxygen in aquatic ecosystems.

Human movement can spread pathogens into new regions where native species lack resistance.

An introduced fungal disease spread by bark beetles that killed large numbers of elm trees.

A water mold disease introduced to susceptible crops, causing widespread potato failure.

Long-term shifts in temperature and precipitation that alter habitats, species ranges, and ecosystem processes.

Large-scale tree removal that destroys habitat, fragments forests, and changes community structure.

Conversion of natural land into cities, causing habitat fragmentation, pollution, and heat island effects.

Growing one crop over large areas, reducing biodiversity and simplifying ecosystem structure.

Periodic warming of the tropical Pacific that shifts global weather, rainfall, and ecosystem conditions.

Tectonic plate movement that changes landmass positions, isolating or connecting populations over time.

A mass extinction event caused by asteroid impact that drastically reshaped global ecosystems.