Energy flow through trophic levels — practice questions

Question 1 · difficulty L1 · recall

A food chain beginning with dead organic matter:

• A. predator chain only
• B. detritus food chain
• C. producer chain
• D. grazing food chain

Question 2 · difficulty L1 · recall

A food chain beginning with living green plants:

• A. detritus food chain
• B. parasitic chain only
• C. grazing food chain
• D. decomposer-free chain

Question 3 · difficulty L2 · understanding

The approximate fraction of energy transferred from one trophic level to the next in the classic ecological rule:

• A. 50 percent
• B. 100 percent
• C. 1 percent
• D. 10 percent

Question 4 · difficulty L2 · understanding

Why is energy flow through an ecosystem considered unidirectional?

• A. Energy repeatedly cycles between all trophic levels
• B. Energy dissipates as heat between trophic levels
• C. Consumers return all energy to producers
• D. Sunlight is recycled by decomposers

Question 5 · difficulty L3 · understanding

Match the trophic levels with their correct species examples in grassland ecosystem. (A) Fourth trophic level (i) Crow (B) Second trophic level (ii) Vulture (C) First trophic level (iii) Rabbit (D) Third trophic level (iv) Grass Select the correct option

• A. (A) $$\to$$ (iv), (B) $$\to$$ (iii), (C) $$\to$$ (ii), (D) $$\to$$ (i)
• B. (A) $$\to$$ (ii), (B) $$\to$$ (iii), (C) $$\to$$ (iv), (D) $$\to$$ (i)
• C. (A) $$\to$$ (i), (B) $$\to$$ (ii), (C) $$\to$$ (iii), (D) $$\to$$ (iv)
• D. (A) $$\to$$ (iii), (B) $$\to$$ (ii), (C) $$\to$$ (i), (D) $$\to$$ (iv)

Question 6 · difficulty L4 · analysis

If producers store 10,000 units of energy, approximately how much would be available to secondary consumers under the 10% law?

• A. 10 units
• B. 1,000 units
• C. 100 units
• D. 9,000 units