Unit 8 Ecology (AP Biology) - Vocabulary Flashcards

Vocabulary flashcards covering key ecology concepts from AP Biology Unit 8 notes.

Ecology

The study of interactions among organisms and their environment.

Ecosystem

A system of living organisms and their physical/chemical environment interacting as a unit.

Community

All the populations of different species living and interacting in a region.

Population

A group of individuals of a single species living in the same general area.

Population ecology

The study of how and why populations grow, shrink, and interact with their environment.

Carrying capacity (K)

The maximum population size the environment can sustain indefinitely under current conditions.

Density-dependent factors

Factors whose effects intensify with increasing population size (e.g., resources, disease, waste).

Density-independent factors

Factors that affect population size regardless of density (e.g., natural disasters).

Logistic growth model

A population growth model that levels off at carrying capacity due to limiting factors.

Clumped distribution

Individuals clustered in patches due to resource patches or social interactions.

Random distribution

Individuals distributed unpredictably, often from random dispersal.

Uniform distribution

Evenly spaced individuals, often due to territoriality.

Type I survivorship

High survival of offspring early in life, mortality increases with age.

Type II survivorship

Constant mortality rate across the life span.

Type III survivorship

High early mortality; those that survive have higher survival later.

Semelparity

A single, massive reproductive event followed by death.

Iteroparity

Multiple reproductive events across a lifetime.

Competition

Minus-minus interaction where species compete for the same resources; can lead to competitive exclusion or niche partitioning.

Niche partitioning

Evolution of species to use different resources or areas to reduce competition and coexist.

Predation

Interaction where a predator feeds on prey; involves adaptations like camouflage or warning colors.

Cryptic coloration

Camouflage that hides an organism from detection.

Aposematic coloration

Warning coloration indicating toxicity or venom.

Müllerian mimicry

Two or more unpalatable species share similar warning coloration.

Batesian mimicry

A harmless species imitates the warning signals of a harmful species.

Mutualism

A symbiotic relationship where both species benefit.

Commensalism

One species benefits while the other is unaffected.

Parasitism

One benefits at the expense of the host; includes endo- and ecto-parasites.

Keystone species

A species with disproportionately large impact on community structure; removal dramatically changes the system.

Biodiversity

The variety of life in a region, measured by species richness and evenness.

Disturbance

An event (e.g., fire, flood) that changes community structure and resources.

Intermediate disturbance hypothesis

Maximum species diversity occurs at intermediate levels of disturbance.

Ecological succession

The gradual change in species composition of a community over time.

Primary succession

Succession starting from bare rock with pioneer organisms like lichens and mosses.

Secondary succession

Succession after a disturbance that leaves soil intact; typically faster.

Decomposers

Organisms (bacteria, fungi) that break down dead matter and recycle nutrients.

Nutrient cycles

Movement of elements (water, carbon, nitrogen, phosphorus) through ecosystems.

Nitrogen cycle

Cycle including N2 gas, fixation by bacteria or lightning, and usable nitrites/nitrates.

Nitrogen fixation

Conversion of atmospheric N2 into usable forms like nitrites and nitrates.

Biomе

Large regional-scale community characterized by climate and geography (e.g., rainforest, desert, tundra).

10% rule

Only about 10% of energy is transferred to the next trophic level.

Food web

A network of feeding relationships showing energy flow and potential cascading effects.

Trophic levels

Hierarchical levels in a food chain: producers, primary consumers, secondary consumers, etc.