4.2 Energy Flow in Ecosystems

Which of the following best describes a food web? 

• a.  A single pathway of energy flow 

• b.  A complex network of feeding interactions 

• c.  A series of decomposers breaking down matter 

• d.  A hierarchy of predators 

In a pyramid of energy, what percentage of energy is typically transferred from one trophic level to the next? 

• 1%

• 10%

• 25%

• 50%

What is phytoplankton's role in aquatic food webs? 

• Primary producer

• Decomposer

• Primary consumer

• Tertiary consumer

An inverted pyramid of numbers might occur in an ecosystem where: 

• There are more producers than consumers. 

• There are more primary consumers than top predators. 

• Higher trophic levels have more organisms than lower levels. 

• d. Energy is lost as heat at each level.

Energy flows in a ------------------- direction through ecosystems, from producers to consumers.

A food chain is a series of organisms through which ----------------------is transferred from one to another.