Look for ocean-dwelling organisms that perform chemosynthesis.

Look for phytoplankton that perform photosynthesis.

Look for soil bacteria that convert atmospheric nitrogen to nitrates.

Look for soil bacteria that convert nitrates to nitrogen gas.

All harness the energy of sunlight through the process of photosynthesis.

All take in energy to assemble energy-rich compounds.

All are small, single-celled organisms, such as bacteria and algae.

All take in food and break it apart to release energy.

either producers or other consumers

producers only

nonliving sources, such as sunlight

other consumers only

Energy flows between primary producers and consumers, in either direction.

Energy flows from consumers to primary producers, in one direction only.

Energy flows from primary producers to consumers, in one direction only.

Energy flows between primary producers and consumers, in an endless cycle.

the total biomass in each trophic level

the total amount of energy in the ecosystem

the relative amount of energy available at each trophic level

the conservation of energy as energy transfers between organisms

The amount of biomass decreases.

The amount of biomass increases.

The amount of biomass varies only slightly, and may increase or decrease.

The amount of biomass varies widely, and both increases and decreases.

Matter flows in a one-way direction through food chains and food webs.

Matter cycles between trophic levels in food chains and food webs.

Matter is made and destroyed as it is used by living things.

Matter cycles through food webs and biogeochemical cycles.

from the hydrosphere to the geosphere

completely within the hydrosphere

from the hydrosphere to the atmosphere

from the biosphere to the hydrosphere

oxygen

sodium

calcium

chlorine

Matter cycles and energy flows through pond organisms from primary producers to a series of consumers.

Matter, but not energy, flows through pond organisms from primary consumers to a series of consumers.

Energy cycles through pond organisms, and returns to primary consumers through the actions of decomposers and detritivores.

Energy and matter flow in opposite directions through pond organisms between primary producers and consumers.

sunfish, snail, algae, crayfish

snail, algae, sunfish, crayfish

algae, snail, sunfish, crayfish

algae, sunfish, crayfish, heron

The model shows that their combined effects determine the amount of solid carbon compounds in the geosphere.

The model shows that their combined effects determine the level of carbon dioxide that dissolves in the hydrosphere.

The model shows that they have identical effects on carbon dioxide levels in the atmosphere.

The model shows that they have opposite effects on carbon dioxide levels in the atmosphere.

arrow 1

arrow 2

arrow 3

arrow 4

Yes, because water is a reactant, or input, of photosynthesis.

Yes, because water is a product, or output, of photosynthesis.

No, because water is necessary for photosynthesis but not changed by it.

No, because water is not involved in photosynthesis.

Plants and other photosynthetic organisms provide food for consumers, who perform cellular respiration.

Plants and other photosynthetic organisms change into fossil fuels over time.

Photosynthesis acts to remove carbon dioxide directly from the atmosphere.

Photosynthesis traps carbon dioxide in the soil.

rely on other organisms for their energy and food supply.

consume plant and animal remains and other dead matter.

use energy they take in from the environment to concert inorganic molecules into complex organic molecules.

obtain energy by eating plants only.

food web.

food chain.

pyramid of numbers.

pyramid of biomass.

pyramid of enerygy.

pyramid of numbers.

pyramid of biomass.

biogeochemical cycle.

Matter is transferred in one direction through the biosphere.

Biogeochemical cycles transform and reuse molecules.

The total amount of matter decreases over time.

Human activity does not affect the movement of matter.

biogeochemical cycles.

water cycles.

pyramids of energy.

ecological pyramids.