Ap bio unit 8 vocab terms

Behavior

How an organism responds to a stimulus

Stimulus

Any environmental change that triggers a response

Physiology

Internal body functions that help survival

Signaling behavior

Actions used to send messages (ex: bird calls)

Communication

Transfer of information between organisms

Cooperative behavior

Organisms work together for benefit (ex: wolves hunting)

Aposematism

Warning coloration to show danger (ex: bright poison frogs)

Innate behavior

Inborn, automatic (no learning)

Learned behavior

Gained through experience

Endotherm

Maintains body heat internally (mammals)

Ectotherm

Relies on environment for heat (reptiles)

Metabolic rate

How fast energy is used

Diapause

Dormancy during harsh conditions

Organism

One individual

Population

Same species in one area

Community

All populations in an area

Ecosystem

Community + environment

Biome

Large region with similar climate

Abiotic

Nonliving (water, temp)

Biotic

Living (plants, animals)

Energy flow

One-way movement of energy through ecosystem

Nutrient cycling

Recycling of matter (like nitrogen)

Evaporation

Liquid → gas

Condensation

Gas → liquid

Precipitation

Rain/snow

Transpiration

Water loss from plants

Nitrogen (N₂)

Gas in atmosphere

Nitrogen fixation

N₂ → usable form (by bacteria)

Ammonia (NH₃) / Ammonium (NH₄⁺)

Usable nitrogen

Nitrification

NH₃ → NO₂⁻ → NO₃⁻

Nitrite (NO₂⁻)

Intermediate form

Nitrate (NO₃⁻)

Plant-usable form

Assimilation

Plants take in nitrogen

Denitrification

Returns N₂ to atmosphere

Weathering

Rocks break → release phosphate

Leaching

Nutrients washed into soil/water

Absorption

Plants take nutrients

Decomposition

Breakdown returns nutrients

Trophic levels

Feeding positions in food chain

Autotroph

Makes own food (plants)

Heterotroph

Eats others

Herbivore

Eats plants

Carnivore

Eats animals

Omnivore

Eats both

Decomposer

Breaks down dead matter

Detritivore/Scavenger

Eats dead material

Trophic cascade

Changes in one level affect others

Population growth equation

Change in population size

Birth rate

New individuals

Death rate

Individuals lost

Exponential growth

Rapid growth (J-curve)

rmax

Max growth rate

N

Population size

Density

Individuals per area

Density-dependent factors

Depend on population size

Density-independent factors

Not dependent

Logistic growth

Growth slows near limit (S-curve)

Carrying capacity (K)

Max population an environment can support

Species

Organisms that can reproduce together

Niche

Role of organism in ecosystem

Species diversity

Number + abundance of species

Species composition

Types of species present

Simpson's Diversity Index

Measure of biodiversity

Competition

Organisms compete

Symbiosis

Close relationship

Mutualism

Both benefit

Commensalism

One benefits, other unaffected

Parasitism

One benefits, other harmed

Predator-prey

One eats another

Neutral

No effect

Niche partitioning

Species use resources differently

Biodiversity

Variety of life

Keystone species

Species with huge impact

Invasive species

Non-native species that harm ecosystem

Ecosystem disruption

Disturbance to ecosystem

Anthropogenic

Human-caused

Natural

Environmental