Lesson 3.5.3.2

3.5.3.2 Net production of consumers and ecosystem productivity Quiz: AQA Biology, Unit 5

20 questions

Written by Revision Ninja · Last reviewed 11 October 2026

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Lesson 3.5.3.2, Net production of consumers and ecosystem productivity: 20 multiple choice questions for the AQA Biology (7402), Unit 5: Energy transfers in and between organisms, written with Revision Ninja.

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The 20 questions

  1. In the consumer net production equation, N = I - (F + R), what does N represent?

    • Net consumer production
    • Ingested food energy
    • Respiratory heat loss
    • Faeces energy loss

  2. In the consumer net production equation, N = I - (F + R), what does I represent?

    • Net consumer production
    • Inorganic energy
    • Ingested chemical energy
    • Faecal energy loss

  3. In the consumer net production equation, N = I - (F + R), what does F represent?

    • Ingested food energy
    • Respiratory heat loss
    • Faeces and urine
    • Fixed chemical energy

  4. What is the correct definition of primary productivity?

    • Consumer growth rate
    • Total biomass stored
    • Heat energy loss
    • Primary production rate

  5. How is secondary productivity defined in an ecosystem?

    • Consumer production rate
    • Decomposition rate
    • Producer growth rate
    • Total light absorption

  6. A consumer ingests 500 kJ of food. It loses 150 kJ in faeces and urine and 200 kJ in respiration. What is its net production?

    • 50 kJ
    • 150 kJ
    • 500 kJ
    • 350 kJ

  7. A consumer ingests 800 kJ, loses 260 kJ in faeces and urine and 340 kJ in respiration. What is its net production?

    • 400 kJ
    • 540 kJ
    • 200 kJ
    • 100 kJ

  8. A consumer ingests 1000 kJ, loses 400 kJ in faeces and urine and 350 kJ in respiration. What is its net production?

    • 350 kJ
    • 250 kJ
    • 1000 kJ
    • 600 kJ

  9. The NPP of producers in a habitat is 12 000 kJ and the net production of the herbivores that feed on them is 1200 kJ. What is the efficiency of energy transfer?

    • 100%
    • 12%
    • 10%
    • 1%

  10. A consumer has I = 600 kJ, F = 200 kJ and R = 300 kJ. What percentage of its ingested energy becomes net production?

    • 33.3%
    • 50%
    • 16.7%
    • 66.7%

  11. The NPP of producers is 6000 kJ and the net production of a consumer is 300 kJ. What is the efficiency of this energy transfer?

    • 20%
    • 10%
    • 5%
    • 50%

  12. Why is energy transfer efficiency between trophic levels always less than 100%?

    • Increased photosynthesis
    • Equal consumer biomass
    • Complete food digestion
    • Respiratory heat loss

  13. How does simplifying a food web increase energy transfer efficiency to humans?

    • Increases respiration
    • Increases pest species
    • Reduces crop biomass
    • Reduces non-human chains

  14. How does housing livestock in warm environments increase farming efficiency?

    • Reduces respiratory loss
    • Increases heat loss
    • Reduces food intake
    • Increases faecal loss

  15. A farmer records that a herbivore's net production is 80 kJ and it ingested 400 kJ. Which is the efficiency of this consumer based on ingested energy?

    • 40%
    • 5%
    • 80%
    • 20%

  16. Through which processes is energy lost between consecutive trophic levels?

    • Ingestion and absorption
    • Photosynthesis and growth
    • Respiration and waste
    • Transpiration and decay

  17. Why is ecosystem productivity always lower at higher trophic levels?

    • Energy transfer losses
    • Increased producer biomass
    • Higher photosynthetic rate
    • Lower metabolic rate

  18. Which term in N = I - (F + R) represents energy lost through respiration?

    • R
    • N
    • F
    • I

  19. A consumer ingests 2000 kJ and has an efficiency of 15% based on ingested energy. What is its net production?

    • 130 kJ
    • 1700 kJ
    • 300 kJ
    • 15 kJ

  20. Which formula calculates the percentage efficiency of energy transfer between trophic levels?

    • (Output - Input) x 100
    • (Output / Input) x 100
    • (Output x Input) x 100
    • (Input / Output) x 100

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