Ecology Basics
Levels of Organization
Population Ecology
Limiting Factors and Dynamics
Food Webs, Pyramids, and special concepts
100

This term refers to the study of interactions between organisms and their environment.

What is ecology?


100

This is the smallest level of organization — one individual organism.

What is a species?

100

The four characteristics used to study populations.

Density, dispersion, size, and growth rate.


100

The maximum number of organisms an environment can support.

What is carrying capacity?


100

The feeding position of an organism in a food chain.

What is a trophic level?

200

These are the living components of an ecosystem.

What are biotic factors?

200

This term refers to a group of individuals of the same species in one area.

What is a population?

200

 Clumped, uniform, and random describe this.

What is dispersion?

200

Limiting factors that increase in effect as population density increases.

What are density-dependent factors?

200

The diagram showing many overlapping food chains.

What is a food web?

300

These are the nonliving components of an ecosystem.

What are abiotic factors?

300

This level includes all populations living together in one place.

What is a community?

300

Births + immigration vs deaths + emigration control this population statistic.

What is population size?

300

Limiting factors like natural disasters, which affect populations regardless of size.

What are density-independent factors?

300

Energy pyramids, biomass pyramids, and numbers pyramids all show this general idea.

How energy, mass, or organism count change across trophic levels.

400

This term describes the role an organism plays in its environment — including how it gets resources.

What is a niche?

400

This level includes all organisms AND their physical environment.

What is an ecosystem?

400

A J-shaped curve on a graph shows this type of population growth.

What is exponential growth?

400

In a predator–prey graph, which population typically rises first?

The prey population.

400

A species that has an unusually large effect on its ecosystem (example: wolves in Yellowstone).

What is a keystone species?

500

This is the physical place where an organism lives.

What is a habitat?

500

This level includes multiple ecosystems with the same climate and organisms.

What is a biome?

500

The growth pattern where a population slows as it nears carrying capacity — forming an S-curve.

What is logistic growth?

500

Explain why predator and prey curves are offset from each other.

Predator numbers change after prey numbers change, because predators depend on prey availability.

500

The process in which species divide resources so they can live together without intense competition.

What is niche partitioning?