Least abundant in a community; affects its environment by controlling other populations.
What is a keystone species?
100
The study of the interactions of organisms with their physical environment and with each other.
What is ecology?
100
Limit to the number of individuals that can occupy one area at a particular time; growth slows and levels out when it reaches this point. Represented by the letter K.
What is carrying capacity?
100
These consumers are needed in an ecosystem for a balance to occur.
What are herbivores, omnivores, carnivores, and decomposers?
200
The position on a food web, food chain, and/or energy pyramid occupied by an organism representing what it eats and what eats it.
What is a trophic level?
200
A major biotic community characterized by the dominant forms of plant life and the climate.
What is a biome?
200
Nonliving, physical features in an ecosystem that include temperature, water, sunlight, wind, rocks, and soil.
What are abiotic factors?
200
The maximum rate at which a population could increase under ideal conditions.
What is biotic potential?
200
Symbiotic relationship in which two species benefit from one another.
What is mutualism?
300
Energy stored in a trophic level is converted to organic matter at the next level.
What is the 10% rule?
300
Describes how individuals in a population are distributed (i.e. uniform, clumped, random).
What is dispersion?
300
Earthquakes, storms, and natural occurring fires and floods are examples of this.
What are density-independent factors?
300
Factors that increase directly as the population density increases, including competition for food, predation, and disease.
What are density-dependent factors?
300
Describes all the biotic (living) and abiotic (nonliving) resources in the environment used by an organism.
What is a niche?
400
Has the least biomass of any other trophic level in the food chain; least stable and most stable to fluctuations in the population.
What are tertiary consumers?
400
Curve that describes species in which most individuals die young, with only a few organisms surviving long enough to reproduce and beyond.
What is a Type III Curve?
400
The relationship where two organisms live together in close association; one organism benefits, while the other is unaware and unharmed.
What is commensalism?
400
One simple model for population growth includes an environment with unlimited resources, and a population with no predation, parasitism, competition, and immigration/emigration.
What is exponential growth?
400
Having few young, intensive parenting, slow maturation, large young, and multiple times of reproduction are characteristics of this.
What is K-selected species?
500
Poisons that enter the food chain at the producer level and become amplified as they move up the trophic levels.
What is biological magnification?
500
Process in which elements, chemical compounds, and other forms of matter are passed from one organism to another and from one part of the biosphere to another.
What are biogeochemical cycles?
500
The process of sequential rebuilding of an ecosystem after major destruction occurs.
What is ecological succession?
500
When the birth rate equals the death rate?
What is zero population growth?
500
The term used to describe when two species resemble one another in appearance.