52. Ecosystems

What is the term for each step in the transfer of energy and matter within a food web?

On a global scale, energy _____ ecosystems whereas chemical elements _____ ecosystems.

In an energy pyramid, which trophic level contains the greatest amount of available energy?

What percentage of energy from a lower trophic level is typically transferred to the next higher trophic level in an ecosystem?

In an energy pyramid representing a terrestrial ecosystem, which trophic level contains the most energy?

Why are there seldom food chains with more than four trophic levels in an ecosystem?

Energy in most ecosystems must flow through autotrophs because ______.

Which organisms are considered the most important transformers of energy in ecosystems?

Which of the following sequences best represents the flow of energy through living systems?

In the context of energy flow through ecosystems, what percentage of energy is typically transferred from one trophic level to the next?

An ecological pyramid can depict the flow of which of the following between successive trophic levels?

From the producer level, to which trophic level does energy flow directly in an ecosystem?

What is the first step in energy flow through an ecosystem?

Which of the following statements is true about the energy flow in an ecosystem?

In the context of energy flow through ecosystems, what is the primary role of nutrients?