Retake for APES

The average efficiency of energy transfer between trophic levels is approximentley

10%

The maximum efficiency possible in an energy-conversion process that is not limited by the second law of thermodynamics

100%

Which of the following values best represents the amount of energy available for primary consumers in the food chain?

9,300

Which of the following best explains why terrestrial trophic pyramids usually do not have levels higher than tertiary consumers?

A large proportion of energy is lost as heat as it is transferred up the pyramid, so there is not enough energy available to support another level.

Which of the following best describes gross primary productivity in an ecosystem?

Correct. Gross primary productivity is the total rate of photosynthesis of producers in an ecosystem over time.

Of the following organisms, which occupies the lowest trophic level?

Deer

Whcih statement best describes energy transfer in a food web?

Energy from the sun is stored in green plants and transferred to consumers through herbivory

Which of the following best describes the movement of energy in an ecosystem?

Energy is harnessed by producers, and available energy decreases with each trophic level transfer.

For a primary producer, the main function of photosynthesis is to manufacture

Glucose

Which of the following best describes the first law of thermodynamics?

In a closed system of constant mass, the energy involved in any physical or chemical change is neither created nor destroyed, but merely changed from one form to another.

A keystone species is

Is most likely a top predetor

Which of the following best describes the net primary productivity of an ecosystem?

Net primary productivity is the amount of energy lost through respiration by producers subtracted from the gross primary productivity of an ecosystem.

A zebra is an example of a

Primary Consumer

Which of the following best explains why decomposers in soils and water are important to ecosystems?

Recycles nutrients

At which level are eagles that consume fish that eat algae

Secondary consumers

A trophic cascade is the effect of

Tertiary consumer; the abundance of primary consumers

Losses of usable energy between successive trophic levels in an ecosystem are best accounted for by which of the following?

The second law of thermodynamics

Autotrophs

use photosynthesis