BIOLOGY2AP-ECOLOGYTOPICS2-4VOCABULARY

Metabolic rate

The amount of energy an organism uses per unit of time.

Ecosystem

All organisms in a community plus the abiotic factors with which they interact.

Biotic

Living components of an environment (plants, animals, microbes).

Abiotic

Nonliving physical and chemical components of an environment (light, water, temperature, soil).

Endotherm

An animal that generates heat internally to maintain body temperature (warm-blooded).

Ectotherm

An animal that relies on external sources to regulate body temperature (cold-blooded).

Primary producer

Autotroph that makes its own food using sunlight (photosynthesis) or chemicals (chemosynthesis).

Heterotrophs

Organisms that obtain energy by consuming other organisms.

Primary consumer

Herbivore that eats primary producers.

Secondary consumer

Carnivore that eats primary consumers.

Tertiary consumer

Carnivore that eats secondary consumers (top predator in many food webs).

Decomposer

Organism (fungi, bacteria) that breaks down dead organisms and recycles nutrients.

Food chain

A linear sequence of energy transfer through feeding relationships.

Food web

A network of interconnected food chains showing all feeding relationships in an ecosystem.

Primary production

The amount of light energy converted to chemical energy by autotrophs in an ecosystem.

GPP

Total primary production in an ecosystem.

NPP

GPP minus energy used by autotrophs for respiration; represents energy available to consumers.

Secondary Production

The amount of chemical energy in food converted into new biomass by consumers.

Demography

The study of population characteristics such as birth rates, death rates, and growth.

Life table

A chart that tracks survivorship and reproduction rates for a population at different ages.

Survivorship curve

A graph showing the proportion of individuals surviving at each age for a given population.

Exponential growth

Population growth under ideal conditions where resources are unlimited, producing a J-shaped curve.

Life history

The traits that affect an organism’s schedule of reproduction and survival (e.g., age at first reproduction, number of offspring, lifespan).

Density-dependent regulation

Factors that limit population growth more strongly as population density increases (e.g., competition, disease, predation).

Density-independent regulation

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

K-selection

A life history strategy favoring few offspring, high parental investment, and traits that increase survival in stable environments near carrying capacity.

R-selection

A life history strategy favoring many offspring, little parental investment, and traits that maximize reproduction in unpredictable environments.

Population

A group of individuals of the same species living in the same area at the same time, capable of interbreeding.

Population ecology

The study of how populations change over time and space and how they interact with the environment.

Density Dispersion

The pattern of spacing among individuals in a population: clumped, uniform, or random.

Logistic growth

Population growth that slows as it approaches carrying capacity, producing an S-shaped curve.