Food Production
Evaluate how fertilisers, pesticides, biological control and genetically modified crops affect yield and ecosystems.
How to study National 5 Biology
Move between biological structures, processes, experimental evidence, data and justified explanations while using current official materials for exact paper and assignment conditions.
Core concepts
Concept 1
Fertilisers add nitrates that plants use to make amino acids and proteins, increasing potential crop yield.
Exam cue: Write the eutrophication sequence in causal order.
Concept 2
Fertiliser leaching can cause algal blooms, light loss, plant death, bacterial increase and oxygen depletion.
Exam cue: Distinguish accumulation within an organism from increasing toxicity along a food chain.
Concept 3
Persistent pesticides can accumulate in organisms and reach increasing toxic concentrations along food chains.
Exam cue: Balance potential yield benefits against a named environmental consequence.
Concept 4
Biological control and genetically modified crops can provide alternatives to some fertiliser or pesticide use.
Risk pitfalls and guardrails
Saying nitrate is absorbed so plants can make carbohydrates rather than amino acids.
Guardrail: Check the biological level, direction, location, units and whether the evidence supports the strength of the claim.
Skipping bacteria when explaining oxygen depletion after an algal bloom.
Guardrail: Check the biological level, direction, location, units and whether the evidence supports the strength of the claim.
Presenting biological control or GM crops as risk-free.
Guardrail: Check the biological level, direction, location, units and whether the evidence supports the strength of the claim.
Memory anchors
Nitrate use
Plants absorb nitrate to make amino acids and then proteins.
Eutrophication start
Leached fertiliser adds unwanted nitrate and increases algal growth.
Oxygen depletion
Dead algae and plants feed bacteria whose respiration uses dissolved oxygen.
Pesticide accumulation
A pesticide can build up within an organism over time.
Food-chain toxicity
Toxic concentration can increase at successive trophic levels.
Alternatives
Biological control and some GM crops can reduce reliance on pesticides or fertilisers.
Checkpoint rule
Do the check-up only after you can summarize each concept in one sentence and identify one dangerous pitfall from memory.
Knowledge Check (after reading)
Short check-up to confirm understanding of this module.
Check-up Questions
Why do crops need nitrate ions?
How can fertiliser increase crop yield?
Answer all questions to submit.
Next step personalized recommendations
Continue learning
Move forward only after this module is stable.
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