Drugs Flashcards – Cambridge IGCSE (9–1) Biology 0970 (Extended) (2026–2028)

What is a drug?

Any substance taken into the body that modifies or affects chemical reactions in the body.

What are antibiotics?

Drugs used to treat bacterial infections by killing bacteria.

Why are antibiotics ineffective against viral infections?

Antibiotics do not affect viruses.

How does antibiotic resistance affect the treatment of bacterial infections?

It reduces the effectiveness of antibiotics against infections caused by the resistant bacteria.

How can antibiotic use make resistant bacteria more common?

The antibiotic kills susceptible bacteria, while resistant bacteria may survive and reproduce, increasing their proportion in the population.

Why does using antibiotics only when essential help limit resistant bacterial populations?

It reduces opportunities for resistant bacteria to be selected and spread.