Explain why diseases caused by fungi are more difficult to treat than diseases caused by bacteria.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
Athlete's foot is a common fungal disease that infects the skin. It can be treated, but the treatment often takes several weeks to work.
Model answer (4 marks)
Fungi are eukaryotic, possessing a nucleus and membrane‑bound organelles that are structurally similar to those in human cells. Consequently, drugs that target fungal cells often affect human cells as well, limiting the selectivity of antifungal agents.
In contrast, bacteria are prokaryotic and lack a nucleus; their cell walls and other structures differ markedly from human cells. This difference allows antibiotics to act on bacterial cells without harming human cells, making bacterial infections easier to treat.
In contrast, bacteria are prokaryotic and lack a nucleus; their cell walls and other structures differ markedly from human cells. This difference allows antibiotics to act on bacterial cells without harming human cells, making bacterial infections easier to treat.
Examiner tips
- Use the word ‘eukaryotic’ and ‘prokaryotic’ to show understanding of cell type differences.
- Explain the consequence of similar cell structures – potential host toxicity – and contrast with bacterial specificity.
- Keep the answer concise and directly linked to the marks given.
Common mistakes
- Confusing the terms eukaryote/prokaryote or omitting the cell‑structure comparison.
- Failing to mention that antifungal drugs can damage human cells.
- Giving extra detail about treatment duration that is not required for the 4‑mark answer.
Mark scheme (4 marks)
- Fungi are eukaryotic (have a nucleus / membrane-bound organelles)
- Human cells are also eukaryotic, so fungi share similar cell structures with human cells
- Drugs that kill fungi may also damage / kill human cells
- Bacteria are prokaryotic and have different cell structures to human cells, so antibiotics can target bacteria without harming human cells
Key terms in this question
Related
- All Eduqas GCSE Biology revision notes →
- How to answer a "Explain" question →
- Decode the mark scheme abbreviations →