Atmosphere & Earth
Energy & Food Webs
Water & Nutrient Cycles
Species & Biodiversity
Populations & Interactions
Conservation & Human Impacts
100

This layer of the atmosphere is closest to Earth and contains most weather phenomena.

What is the troposphere?

100

Organisms that make their own food using sunlight (or chemicals).

What are producers? (or autotrophs)

100

The continuous movement of water from the surface to the atmosphere and back.

What is the hydrological cycle? (or water cycle)

100

The variety of life across all levels, including genes, species, and ecosystems.

What is biodiversity?

100

A symbiotic relationship in which one organism benefits and the other is neither helped nor harmed.

What is commensalism?

100

The intentional release of controlled, low-intensity fires to reduce fuel loads and maintain ecosystem health.

What is a prescribed burn?

200

Term for the solid parts of Earth (rocks, soil, and mantle).

What is the geosphere?

200

Organisms that eat producers; often called herbivores.

What are primary consumers?

200

The movement of carbon among atmosphere, organisms, oceans, and rocks is called this.

What is the carbon cycle?

200

A species that occupies many different habitats or has a wide diet — contrasted with a specialist.

What is a generalist species?

200

The maximum population size that an environment can sustainably support for a species.

What is carrying capacity?

200

The law in the United States that provides protections for listed endangered and threatened species.

What is the Endangered Species Act (ESA)?

300

The atmospheric layer above the troposphere that contains the ozone layer.

What is the stratosphere?

300

The position an organism occupies in a food chain (producer, primary consumer, etc.).

What are trophic levels?

300

When excess nutrients (like phosphorus or nitrogen) cause algal blooms and oxygen depletion in aquatic systems.

What is eutrophication?

300

A species that has a disproportionately large effect on its ecosystem relative to its abundance.

What is a keystone species?

300

A species with many, small offspring and little parental care, often leading to boom-and-bust population cycles.

What are r-selected species?

300

The buildup of a toxin (like DDT) in an individual organism over time.

What is bioaccumulation?

400

The process by which precipitation runs over land into rivers, lakes, and oceans.

What is surface runoff?

400

Organisms that break down dead material and recycle nutrients back into ecosystems.

What are decomposers?

400

The term for water stored beneath Earth's surface in saturated rock or soil layers.

What is groundwater?

400

A measure of the number of different species in a given area (a component of biodiversity).

What is species diversity?

400

The gradual, directional change in species composition in an area over time after a disturbance.

What is ecological succession? (primary vs. secondary depending on context)

400

The process by which toxin concentrations increase up a food chain, causing higher levels in predators.

What is biomagnification?

500

A large underground, permeable rock formation that can store and transmit groundwater.

What is an aquifer?

500

The consumer that eats secondary consumers; often near the top of a food chain.

What are tertiary consumers?

500

A cycle that lacks an atmospheric gaseous phase and is commonly slow because phosphorus is mostly bound in rocks and soils.

What is the phosphorous cycle?

500

When natural habitats are broken into smaller, isolated patches by human activities; this reduces gene flow.

What is habitat fragmentation?

500

When two species evolve together and influence each other's adaptations over time.

What is coevolution?

500

A conservation method that stores seeds of plants (often wild species) to preserve genetic diversity.

What is a seed bank?

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