Explain how a pathogen can be spread from one plant to another in a garden.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
Rose black spot is a fungal disease that spreads rapidly through gardens, particularly in wet conditions. It causes purple or black spots on leaves, which then turn yellow and drop early.
Model answer (4 marks)
Pathogens can be spread by water or rain splashing spores or the pathogen from one plant to another.
Pathogens can be spread by wind carrying spores or the pathogen to other plants.
Pathogens can be spread by insects or other vectors that carry the pathogen from plant to plant.
The pathogen enters the plant and infects a new plant through damaged tissue, stomata or wounds, allowing the disease to develop.
Pathogens can be spread by wind carrying spores or the pathogen to other plants.
Pathogens can be spread by insects or other vectors that carry the pathogen from plant to plant.
The pathogen enters the plant and infects a new plant through damaged tissue, stomata or wounds, allowing the disease to develop.
Examiner tips
- Use the exact phrases from the mark scheme (e.g. "water / rain splashing", "wind carrying spores", "insects / vectors", "damaged tissue / stomata / wounds").
- Keep each point short and separate, matching the four marks.
Common mistakes
- Using vague terms like "spreading" without specifying the mechanism; "spreading by contact" is not credited.
- Failing to mention all four mechanisms – missing any one point loses marks.
Mark scheme (4 marks)
- Pathogens can be spread by water / rain splashing spores or the pathogen between plants
- Pathogens can be spread by wind carrying spores / the pathogen to other plants
- Pathogens can be spread by insects / vectors that carry the pathogen from plant to plant
- Pathogen enters the plant / infects a new plant through damaged tissue / stomata / wounds, allowing the disease to develop
Key terms in this question
Related
- Revision notes: Plant disease (Bio only) →
- How to answer a "Explain" question →
- Decode the mark scheme abbreviations →
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