Trophic Levels

Ch. 5.1 How Ecosystems Work

Food Chain vs. Web

• Chain: Path in which energy is transferred from one organism to the next.

• Web: Shows the energy flow and possible feeding relationships within an ecosystem.

Multiple Choice

Which of the following is most likely to cause the greatest decrease in the snake population?

• an increase in the grasshopper population

• a decrease in the mouse population

• a decrease in the vulture population

• a decrease in the hawk population

Multiple Choice

Phytoplankton --> Krill --> Fish --> Sea Gull

Which organism in this food chain is the primary consumer?

• phytoplankton

• krill

• fish

• sea gull

Multiple Choice

Which of the following is most likely to cause an increase in the croaker population?

• an increase in the anchovy population

• a decrease in the crab population

• a decrease in the bluefish population

• a decrease in the algae population

Trophic Levels

• Each step through which energy is transferred in a food chain/web.

• Each time energy is transferred from one organism to another, less energy is available at the next trophic level.

• Cellular respiration releases heat.

Multiple Choice

In which level are producers found?

• A

• B

• C

• D

Multiple Choice

Energy flows into an ecosystem through producers and is ultimately lost as...

• food

• carbon dioxide

• light

• heat

Multiple Choice

In which level are secondary consumers found?

• A

• B

• C

• D

Multiple Choice

What is the producer in this food web?

• anchovy

• shrimp

• algae

• snail

The decreased amount of energy at each trophic level affects the organization of an ecosystem.

• Pyramid shape

Open Ended

How do humans disrupt the stability of trophic levels within an ecosystem?