Understanding Ecosystems: From Food Chains to Biodiversity

What is an autotroph?

• An organism that consumes other organisms

• An organism that produces its own food

• A type of decomposer

• A secondary consumer

What is the primary source of energy in most ecosystems?

• Tertiary consumers

• Decomposers

• Secondary consumers

• Producers

What percentage of energy is transferred from one trophic level to the next?

• Around 25%

• About 50%

• Exactly 10%

• Less than 10%

What happens to the energy not stored at each trophic level?

• It is transferred to decomposers directly

• It is stored as fat in the organisms

• It is lost as heat or remains undigested

• It is used for reproduction

What happens if a primary consumer is removed from a food chain?

• The ecosystem becomes more stable

• Secondary consumers will have more food

• It can harm other organisms in the chain

• There is no significant effect

How does the removal of an apex predator affect a food chain?

• It increases biodiversity immediately

• It can lead to an overpopulation of certain species

• It increases the energy available to primary consumers

• It has no effect on the food chain

What does a food web demonstrate that a food chain does not?

• Interactions among a variety of producers and consumers

• The singular path of energy flow

• The flow of energy in an ecosystem

• The role of autotrophs

Which of the following best describes a food web?

• A representation of multiple food chains that interact in an ecosystem

• A linear sequence of who eats whom in an ecosystem

• A diagram showing only the decomposers in an ecosystem

• A system that shows only the primary consumers and producers

Why is biodiversity important for ecosystems?

• It ensures that all organisms are predators

• It limits the variety of organisms in an area

• It decreases the resilience of ecosystems to changes

• It contributes to the sustainability of the ecosystem

What role do decomposers play in an ecosystem?

• They only consume living organisms

• They are primary consumers

• They break down dead organisms and recycle nutrients

• They store energy from the sun