Ash dieback is a communicable disease in plants caused by the fungal pathogen Hymenoscyphus fraxineus. Describe how ash dieback spreads between trees and explain the measures that can be taken to limit its spread.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
Model answer (5 marks)
Ash dieback spreads by airborne spores that are carried by wind from infected trees to healthy ones.
It also spreads when infected ash plants or logs are moved, for example during pruning or timber transport.
People and animals can carry spores on their clothing, shoes, cars or equipment, spreading the disease to new sites.
To limit spread, wash animals, cars and boots before leaving an infected area.
Avoid moving infected plants and burn or destroy infected trees to prevent further transmission.
It also spreads when infected ash plants or logs are moved, for example during pruning or timber transport.
People and animals can carry spores on their clothing, shoes, cars or equipment, spreading the disease to new sites.
To limit spread, wash animals, cars and boots before leaving an infected area.
Avoid moving infected plants and burn or destroy infected trees to prevent further transmission.
Examiner tips
- Use the exact phrase "airborne spores" for the first point. Include both plant movement and human/animal vectors. Show the two control measures: cleaning and removal/burning.
- common_mistakes
- :
- Confusing spores with spores as a general term. Forgetting to mention human/animal vectors. Using vague words like "contamination" instead of "spores carried by wind.
Mark scheme (5 marks)
- Ash dieback spreads through the air (airborne transmission of spores / fungal spores carried by wind)
- Ash dieback spreads through the movement of diseased ash plants or infected logs
- Ash dieback can be carried on people or animals moving through infected areas
- Washing animals, cars and boots when leaving an infected area prevents spread (linked to limiting spread)
- Do not move infected plants / burn infected trees to limit spread
Key terms in this question
ash dieback · Hymenoscyphus fraxineus · communicable disease · pathogen
Related
- All Eduqas A-Level Biology revision notes →
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- Decode the mark scheme abbreviations →
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