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QLDBiologyQuick questions
Unit 3: Biodiversity and the interconnectedness of life
Quick questions on Energy flow, food webs and trophic efficiency (QCE Biology Unit 3)
9short Q&A pairs drawn directly from our worked dot-point answer. For full context and worked exam questions, read the parent dot-point page.
What is producers (autotrophs)?Show answer
Producers fix energy from an abiotic source into chemical energy in organic molecules.
What is consumers (heterotrophs)?Show answer
Consumers obtain energy by eating other organisms.
What is biomass?Show answer
Biomass is the total mass of living organic matter (dry mass, in g or kg) per unit area or volume.
What is productivity?Show answer
Productivity is the rate at which producers fix energy (or organic matter) per unit area per unit time.
What is the 10 per cent rule?Show answer
On average, only around 10 per cent of the energy at one trophic level is incorporated into biomass at the next level. The other 90 per cent is lost as:
What are energy pyramids?Show answer
Three pyramid forms appear in QCAA stimulus.
What is q1?Show answer
Distinguish between gross primary productivity (GPP) and net primary productivity (NPP) and explain why NPP is the relevant value for supporting consumers. [3 marks]
What is q2?Show answer
A food chain shows producer biomass 10,000 kJ/m^2/year, primary consumer 950, secondary consumer 95, tertiary consumer 9 kJ/m^2/year. Calculate trophic efficiency between each level and comment on whether the 10 percent rule holds. [3 marks]
What is q3?Show answer
Refer to a Moreton Bay seagrass meadow. (a) Identify the principal producer and two primary consumers. (b) Predict the effect of removing dugongs on seagrass biomass.