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QLDBiologyQuick questions
Unit 3: Biodiversity and the interconnectedness of life
Quick questions on Carbon, nitrogen and water cycles and human impacts (QCE Biology Unit 3)
8short 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 the carbon cycle?Show answer
Carbon moves between an atmospheric pool (CO2 and methane), an oceanic pool (dissolved CO2, bicarbonate, carbonate), a lithospheric pool (carbonate rocks, fossil fuels) and a biospheric pool (living and dead organic matter).
What is the nitrogen cycle?Show answer
Nitrogen is the most abundant atmospheric gas (78 per cent of air as N2) but is unusable to most organisms in that form because of the strong triple bond. Specialist microorganisms perform the key transformations.
What is the water cycle?Show answer
Water moves between the atmosphere (water vapour), the hydrosphere (oceans, lakes, rivers, groundwater), the cryosphere (ice and snow) and the biosphere (water inside organisms).
What is how the three cycles connect?Show answer
The cycles are not independent.
What is naming "bacteria" without specifying?Show answer
QCAA likes named genera or specific functional groups (Rhizobium for symbiotic fixation, Nitrosomonas for nitrification, Pseudomonas for denitrification).
What is forgetting decomposers?Show answer
Decomposers complete every cycle by returning matter from dead organic material to inorganic pools.
What is conflating eutrophication with simple pollution?Show answer
Eutrophication is enrichment with nutrients (typically N and P) that triggers algal blooms, oxygen depletion (hypoxia) on decomposition, and fish kills. Name the mechanism, not just "nutrients are bad".
What is ignoring water cycle changes from land clearing?Show answer
Vegetation removal in Australia is the largest driver of dryland salinity, and this is examinable.