AP Bio Unit 8 (Ecology) Vocab

Ethology

The study of how evolutionary processes shape inherited behaviors

Behavior

An animal’s response to a stimulus (internal or external)

Proximate cause

How a behavior occurs or how it is modified

Innate behaviors

Born behaviors, do not need to learn (intinctive)

Learned behaviors

Behaviors shaped by experiences

Ultimate cause

Why a behavior occurs (in context of natural selection)

Fixed action patterns

A sequence of unlearned acts directly linked to a stimulus

Stimulus response chain

A sequence of stimulus-response components occurring together, where each response creates the stimulus for the next action

Directed movements

Movements towards or away from a stimulus

Pheromones

Chemical substances secreted or excreted by an organism that trigger social, behavioral, or physiological responses in other members of the same species

Sign Stimulus

An external environmental cue that triggers a fixed action pattern

Migration

A regular, long-distance change in location

Kinesis

A change in the rate of movement or the frequency of turning movements in response to a stimulus (nondirectional)

Taxis

Directional movement towards (positive) or away from (negative) a stimulus

Phototaxis

Movement in response to light

Chemotaxis

Movement in response to chemical signals

Geotaxis

Movement in response to gravity

Learning

How organisms modify their behavior due to experience, practice, or observation

Imprinting

A long-lasting behavioral response to an individual

Spacial learning

Establishing memories based upon the spacial structure of the animal’s surroundings

Cognitive Map

Mental representation of an organism’s environment that encodes spatial relationships between landmarks, allowing for navigation and distance calculation

Associative learning

The ability to associate one environmental feature with another

Social learning

Learning through observations and imitations of the observed behaviors

Foraging

Ants following pheromone trail to food source

Altruism

Selfless behavior; An individual behaves in a way that benefits others, but not itself

Phototropism

A directional response that allows plants to grow towards (and in some cases away from) a source of light

Photoperiodism

Allows plants to develop in response to day length; Plants flower only at certain times of year

Evaporation

Liquid → gas

Transpiration

Evaporation in plants

Condensation

Gas → liquid

Precipitation

Condensation grows too large and falls

Photosynthesis

Plants take CO2 from atmosphere to make glucose

Cellular respiration

Glucose broken down to make ATP; Respiration produces CO2 → atmosphere

Decomposition

Organism dies, decomposers break down carbon compounds → CO2 → atmosphere

Combustion

Burning fossil fuels → CO2 → atmosphere

Fixation

Nitrogen fixing bacteria converts nitrogen gas in air → ammonia in soil

Assimilation

Ammonia & nitrates taken by plants → biological molecules (DNA & proteins)

Nitrification

Ammonia → NItrates by adding O2

Ammonification

Organisms die & decompose → Ammonia in soil

Denitrification

Denitrifying bacteria → nitrates in soil → nitrogen gas in air

Metabolic rate

The total amount of energy an animal uses in a unit of time

Ecosystem

The sum of all the organisms living in a given area and the abiotic factors they interact with

Biotic

Living, or once living, components of an environment

Abiotic

Nonliving (physical & chemical) properties of the environment

Endotherm

Use thermal energy from metabolism to maintain body temperature

Ectotherm

Use external sources (ie - sun/shade or other organisms) to regulate body temperature

Primary producer

Use light energy to synthesize organic compounds

Heterotrophs

Rely on autotrophs because they cannot make their own food

Primary consumer

Herbivore

Secondary consumer

Carnivores that eat primary consumers (herbivores)

Tertiary consumer

Carnivores that eat secondary consumers (carnivores)

Quaternary consumer

Carnivores that eat tertiary consumers (carnivores); If they have no natural predators, they are apex predators

Decomposer

Small organisms (bacteria, fungi) that get energy from detritus (nonliving organic material) produced at other trophic levels

Scavenger

Animals that consume dead/decaying organisms (plants/animals)

Biogeochemical cycles

Nutrient cycles that contain both biotic and abiotic factors

Food chain

The transfer of food energy up the trophic levels

Food web

Linked food chains

GPP

Total primary production in an ecosystem

NPP

The GPP minus energy used by the primary producers for respiration

Primary production

The amount of light energy that is converted to chemical energy

Secondary production

The amount of chemical energy in a consumer’s food that is converted to new biomass

Demography

The study of the vital statistics of populations and how they change over time

Life table

An age-specific summary of the survival pattern of a population

Survivorship curve

A graph that shows the proportion of individuals in a population

Exponential growth

A population living under ideal conditions (ie - easy access to food, abundant food, free to reproduce, etc)

Life history

The pattern of how an organism grows, develops, reproduces, and survives throughout its life

Density-dependent regulation

As a population increases, factors can slow or stop growth by decreasing birth rate and increasing death rate

K-selection

Selection for life history traits that are sensitive to population density (density-dependent selection)

Density-independent regulation

Factors that exert their influence on population size, but the birth/death rate of a population does NOT change

R-selection

Selection for life history traits that maximize reproductive success (density-independent selection)

Population

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

Population ecology

Analyzes the factors that affect population size and how and why it changes over time

Density

The number of individuals per unit area

Dispersion

The pattern of spacing among individuals within a population

Logistic Growth

The per capita rate as the population size nears its carrying capacity

Community

A group of populations of different species living closely and capable of interacting

Habitat

A place or part of an ecosystem occupied by an organism

Ecological Niche

The role and position a species has in its environment

Fundamental Niche

The niche potentially occupied by the species if there were no limiting factors (predators, competitors, etc)

Realized Niche

The portion of the fundamental niche the species actually occupies

Interspecific Interactions

Competition between individuals of different species

Competition

-/- relationship where two or more individuals compete for the same resource

Niche partitioning

Natural selection drives competing species into different patterns of resource use, or different niches

Predation

± relationship where one species (predator) kills and eats the other species (prey)

Herbivory

± relationship where one organism eats part of a plant or algae

Symbiosis

Where two or more species live in direct contact with one another

Parasitism

(±) when one organism (parasite) derives nourishment from another (host)

Mutualism

(+/+) when both organisms benefit from the relationship

Commensalism

(+/0) When one organism benefits and the other is neither harmed nor benefitted

Facilitation

(+/+ OR 0/+) when one species has a positive effect on the survival and reproduction of another without intimate association of symbiosis

Biodiversity

The variety of life in a given area or on earth as a whole

Species richness

The number of different species

Relative abundance

The proportion each species represents of all the individuals in the community

Keystone species

Not usually abundant, but other species in an ecosystem rely on them because of their important ecological niches

Ecological succession

The gradual process by which the species composition of a community changes and develops over time after a disturbance

Primary succession

A series of changes on an entirely new (previously lifeless) habitat that has not been colonized

Secondary succession

A series of changes that clears an existing community, but leaves the soil intact

Disturbance

An event that changes a community by removing organisms from it or altering resource availability

Heterozygote advantage

Individuals with two different alleles for a good gene have greater fitness than individuals with either homozygous genotype, helping maintain genetic diversity

Biomagnification

Compounds like toxins/pollutants/contaminants