Antibiotics
Cambridge A-Level Biology (9700) · Unit 10: Infectious disease · 8 flashcards
Antibiotics is topic 10.2 in the Cambridge A-Level Biology (9700) syllabus , positioned in Unit 10 — Infectious disease , alongside Infectious diseases. In one line: Consequences include increased treatment failures, longer hospital stays, higher medical costs, and increased mortality rates from infections that were once easily treatable.
Marked as AS Level: examined at AS Level in Paper 1 (Multiple Choice), Paper 2 (AS Structured Questions) and Paper 3 (Advanced Practical Skills). The same content may also be assumed in Paper 4 (A Level Structured Questions).
The deck below contains 8 flashcards — 2 definitions and 6 key concepts — covering the precise wording mark schemes reward. Use the 2 definition cards to lock down command-word answers (define, state), then move on to the concept and calculation cards to handle explain, describe, calculate and compare questions.
Some consequences of widespread antibiotic resistance
Consequences include increased treatment failures, longer hospital stays, higher medical costs, and increased mortality rates from infections that were once easily treatable.
What the Cambridge 9700 syllabus says
Official 2025-2027 spec · AS LevelThese are the exact learning outcomes Cambridge sets for this topic. The candidate is expected to be able to do each of these on the relevant paper.
- outline how penicillin acts on bacteria and why antibiotics do not affect viruses
- discuss the consequences of antibiotic resistance and the steps that can be taken to reduce its impact
Cambridge syllabus keywords to use in your answers
These are the official Cambridge 9700 terms tagged to this section. Mark schemes credit responses that use the exact term — weave them into your answers verbatim rather than paraphrasing.
Tips to avoid common mistakes in Antibiotics
- › Always capitalize the Genus name and use lowercase for the species epithet; e.g., Mycobacterium tuberculosis.
How does penicillin weaken bacterial cell walls?
Penicillin inhibits the enzyme transpeptidase, preventing peptidoglycan cross-linking in bacterial cell walls. This weakens the cell wall, causing the bacterium to lyse due to osmotic pressure, ultimately killing the bacteria.
Why are viruses unaffected by antibiotics like penicillin?
Viruses lack cell walls and do not perform metabolic processes targeted by antibiotics. Penicillin specifically targets peptidoglycans in bacterial cell walls, structures absent in viruses.
Describe the mechanism of antibiotic resistance in bacteria.
Bacteria can develop resistance through various mechanisms, including enzymatic degradation of the antibiotic (
Outline how horizontal gene transfer contributes to the spread of antibiotic resistance.
Horizontal gene transfer, including conjugation, transduction, and transformation, allows bacteria to share resistance genes. This can rapidly disseminate resistance across different bacterial species, exacerbating the problem.
What are some consequences of widespread antibiotic resistance?
Consequences include increased treatment failures, longer hospital stays, higher medical costs, and increased mortality rates from infections that were once easily treatable.
What is an example of a 'superbug' and why is it concerning?
Methicillin-resistant Staphylococcus aureus (MRSA) is a 'superbug'. It is resistant to many antibiotics, making infections difficult to treat and leading to serious health complications and increased mortality.
Describe steps that can be taken to reduce the impact of antibiotic resistance.
Strategies include reducing unnecessary antibiotic use (
How does antibiotic overuse in agriculture contribute to resistance?
Routine use of antibiotics in livestock promotes the development and spread of resistant bacteria in animals. These bacteria can then be transferred to humans through the food chain or direct contact, increasing antibiotic resistance in humans.
More topics in Unit 10 — Infectious disease
Antibiotics sits alongside these A-Level Biology decks in the same syllabus unit. Each uses the same spaced-repetition system, so progress in one informs the next.
Key terms covered in this Antibiotics deck
Every term below is defined in the flashcards above. Use the list as a quick recall test before your exam — if you can't define one of these in your own words, flip back to that card.
How to study this Antibiotics deck
Start in Study Mode, attempt each card before flipping, then rate Hard, Okay or Easy. Cards you rate Hard come back within a day; cards you rate Easy push out to weeks. Your progress is saved in your browser, so come back daily for 5–10 minute reviews until every card reads Mastered.
Study Mode
Rate each card Hard, Okay, or Easy after flipping.