Explain how using biological control can help improve food security.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
Farmers lose a significant proportion of their crops each year to pests such as insects and fungi. One approach to reducing these losses is biological control, which involves introducing a natural predator or pathogen to reduce pest populations.
Model answer (4 marks)
Biological control introduces a natural predator or pathogen that reduces the numbers of a pest species.
This lower pest population means less damage to crops, so the yield is higher.
A higher yield gives more food for the population, improving food security.
Unlike chemical pesticides, biological control leaves no harmful residues, does not harm non‑target organisms, and is self‑sustaining, making it a sustainable way to maintain food security.
This lower pest population means less damage to crops, so the yield is higher.
A higher yield gives more food for the population, improving food security.
Unlike chemical pesticides, biological control leaves no harmful residues, does not harm non‑target organisms, and is self‑sustaining, making it a sustainable way to maintain food security.
Examiner tips
- Use the exact phrase ‘reduces the numbers of a pest species’ to gain full credit for the first point.
- Show the chain: predator → fewer pests → less crop damage → higher yield → more food available.
- Mention the sustainability benefits to cover the last point.
- Keep the answer concise – 4 marks, so one sentence per point is enough.
Common mistakes
- Confusing biological control with chemical pesticides – students sometimes describe chemical residues instead of the lack of them.
- Failing to link higher yield directly to improved food security – students may stop at ‘more food produced’ without stating the security aspect.
- Using vague terms like ‘natural method’ without specifying predator/pathogen or sustainability benefits.
Mark scheme (4 marks)
- Biological control involves introducing a natural predator (or pathogen/parasite) to reduce the numbers of a pest species
- This reduces the pest population, so less of the crop is damaged or destroyed
- A greater crop yield means more food is produced / available
- Unlike pesticides, biological control does not leave chemical residues on crops / does not harm non-target organisms / is a long-term, self-sustaining method — so it is a sustainable way to maintain food security
Key terms in this question
biological control · food security
Related
- All Edexcel GCSE Biology (1BI0) revision notes →
- How to answer a "Explain" question →
- Decode the mark scheme abbreviations →