Explain why the development of antibiotic-resistant bacteria is a serious concern for human health.

Eduqas GCSE Biology — 2.6.3 Medicines and drugs · Explain · 4 marks · View as Markdown

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

Antibiotic resistance is increasingly reported in hospitals and communities worldwide. Some strains of bacteria, such as MRSA, are resistant to many commonly used antibiotics.

Model answer (4 marks)

Bacteria can acquire mutations that alter the target of the antibiotic or increase drug efflux.
These mutations allow the bacteria to survive the drug and continue to reproduce.
The surviving bacteria pass the resistance genes on to their offspring, so the population becomes resistant.
As a result, antibiotics become ineffective against these strains, making infections harder to treat, potentially fatal and more likely to spread.

Examiner tips

Use the word ‘mutations’ and ‘resistance genes’ to show understanding of the mechanism.
Explain the chain: mutation → survival → reproduction → spread of resistance.
Mention that treatment options are reduced, increasing severity and spread.
Keep answer concise – 4 points, one sentence each.

Common mistakes

Confusing mutation with mutation rate; students say ‘mutation rate increases’ instead of ‘mutations occur’.
Failing to link survival to reproduction and spread of resistance.
Using vague terms like ‘drug resistance’ without explaining why it matters for treatment.

Mark scheme (4 marks)

Bacteria can mutate / mutations occur in bacteria
Resistant bacteria survive and reproduce / are not killed by the antibiotic, passing on resistance to offspring
Antibiotics can no longer be used to treat infections caused by resistant strains / the antibiotic is ineffective against resistant bacteria
Infections become harder to treat / may be fatal / spread more easily because fewer effective treatments are available

Key terms in this question

antibiotic