Which of the following is not a characteristic of ecosystems?

Which biogeochemical cycle(s) does not have a gaseous component?

1) Potassium

2) Sulfur

3) Phosphorus

At what trophic level are eagles that consume fish that eat algae?

At which trophic level do organisms use a process that produces oxygen as a waste product?

At which trophic level are dragonflies that consume mosquitoes that feed on herbivorous animals?

Beginning at the lowest trophic level, arrange the following food chain found on the Serengeti Plain of Africa in the correct sequence.

Which macronutrient is required by humans in the largest amounts?

Roughly what percentage of incoming solar energy is converted into chemical energy by producers?

The net primary productivity (NPP) of an ecosystem is 1 kg C/m²/year, and the energy needed by the producers for their respiration is 1.5 kg C/m²/year. The gross primary productivity (GPP) of such an ecosystem would be:

An ecosystem has an ecological efficiency of 10%. If the producer level contains 10,000 kilocalories of energy, how much energy does the tertiary consumer level contain?

Research at Hubbard Brook showed that stream nitrate concentrations in 2 watersheds were _____ before clear-cutting and that after one watershed was clear-cut, its stream nitrate concentration was _____.

Small inputs of this substance, commonly a limiting factor in aquatic ecosystems, can result in algal blooms and dead zones.

The anticancer drug Taxol was originally extracted from the bark of the Pacific yew tree. This drug is an example of a type of ecosystem service known as _____.

After a severe drought, the productivity in an ecosystem took many years to return to pre-drought conditions. This observation indicates that the ecosystem has _____.