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IGCSE · Cambridge (CIE) · 0610

Apply a stated antibiotic response table

Use pathogen identity and drug-specific evidence without prescribing.

Section 15.1 · Drugs

Drugs pathway · 15.1

Core and Extended; Biology 0610, 2026–2028. Use the stated specimen features and evidence. Diagrams are schematic. Written practice is self-checked

Before you begin

  • Distinguish bacteria from viruses; recall enzymes, chemical reactions, pathogens and reproduction of bacteria.

Work on paper. Try each question before revealing help, and explain why your method works.

Quick readiness check

Which target has no direct response to either antibiotic in this table?

What you will learn

  • Predict biological effects from a labelled model
  • Separate action evidence from treatment decisions

Apply a stated antibiotic response table

Invented effect table: S responds to A and B; R resists A but responds to B; virus V responds to neither antibiotic. Predict effects, not a personal prescription. Original teaching model.

Invented responses to antibiotics A and B — effects, not prescriptions
TargetAntibiotic AAntibiotic B
Bacterial strain SAffectedAffected
Bacterial strain RResistantAffected
Virus VNo direct effectNo direct effect
Drug and antibiotic model reference
FeatureMeaning
Strain SAffected by A and B
Strain RResistant to A; affected by B
Virus VNo direct effect from either antibiotic
LimitEffect table does not establish treatment need or dose

Predict biological effects from a labelled model

The supplied comparison table is an invented biological model with three targets and two antibiotics. Bacterial strain S is affected by A and B. Bacterial strain R is resistant to A but affected by B. Virus V is not affected by either antibiotic. Read both the target category and the individual drug column; the word infection alone does not specify which effect is predicted.

For strain S, both A and B have a stated antibacterial effect in the model. For strain R, A does not have the stated effect but B does. Resistance to A therefore does not establish resistance to B. For virus V, neither antibiotic has a direct antiviral effect. These predictions follow from the supplied table rather than symptoms, colour or an assumption that a stronger drug must affect every pathogen.

Separate action evidence from treatment decisions

A table of biological effects is not a complete clinical selection rule. It does not supply treatment need, side effects, allergies, dose, route or other professional considerations. In the school task, report the predicted effect under the stated conditions rather than instructing a real learner to take A or B. The antibiotic names are deliberately abstract so the exercise remains about target reasoning.

A symptom-relieving drug, an antibody and an antibiotic may be discussed together but have different roles. An improvement in how an organism feels is not the same measurement as whether bacteria or viruses are eliminated. Explain the table’s direct effect and its limits. A secondary bacterial infection during a viral illness would be a separate bacterial target, not evidence that an antibiotic kills the virus.

Pause and explain

What does the table establish about R?

Put the idea to work

Worked example

Predict A and B effects on strain R from the supplied table.

Show the worked solution
  1. R is resistant to A.
  2. R is affected by B in the model.

Answer A has no stated effect on R; B affects R under the supplied model conditions.

Try a topic test

Choose Easy, Normal or Difficult. Save your answers and open worked review after finishing.

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From guided practice to a new situation

Write your answer and reasoning first. Use a hint only if you are stuck. The model solution is for self-checking; your written work is not automatically marked.

1 · Guided

State the model effects of A and B on each target.

Give me a hint

Read both columns for all three targets.

Compare my reasoning
  1. S is affected by A and B; R is resistant to A but affected by B.
  2. Virus V is unaffected by both antibiotics.

S: A and B affect it. R: A does not, B does. Virus V: neither antibiotic has a direct effect.

Look for these in your work

  • Read all three targets
  • Keep drug-specific effects
2 · Independent

Explain why R’s resistance to A does not establish resistance to B.

Give me a hint

Use the separate model evidence.

Compare my reasoning
  1. The resistance is relative to A.
  2. The table states an effect from B.

Resistance is relative to the specified drug; the table separately states that B affects R, so R’s A resistance does not imply B resistance.

Look for these in your work

  • Specify the drug reference
  • Use the separate B result
3 · Transfer

A learner uses the table to choose a personal medication and dose. What important evidence is absent?

Give me a hint

The exercise supplies effects, not a clinical assessment.

Compare my reasoning
  1. Treatment need and personal suitability are not established.
  2. No dose or other clinical considerations are supplied.

The table does not establish personal treatment need, suitability or dose. Its predictions are biological model effects, not a prescription.

Look for these in your work

  • Identify missing clinical evidence
  • Retain the model-only conclusion

Common mistakes

  • Treating resistance to one drug as resistance to both.
  • Turning a model table into a personal prescription.
Recall without your notes

What can you explain now?

What does the table establish about R?

Compare with the explanation

Resistance to A with a separate stated response to B

Responses must be read by drug.

After trying it yourself, choose your next review. This is your self-assessment.

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Make it stick

Apply a drug-specific response table and explain what it cannot establish about personal treatment.

If you needed the solution, close it and solve the problem again from a blank page. A correct answer is stronger when you can explain the reason for each step.

Keep learning Biology

Course scope and assessment

780 sequenced lessons provide 2340 guided, independent and application problems in characteristics, classification, cells, organisation, specimen size, membrane transport, biological molecules, enzymes, plant and human nutrition, plant transport, circulatory systems, the heart, blood vessels, blood, disease transmission, body defences, immunity, gas exchange in humans, respiration energy uses and investigations, aerobic respiration, anaerobic respiration and recovery, excretion in humans, coordination and response, sense organs, hormones, homeostasis, tropic responses, drugs, asexual reproduction, sexual reproduction, sexual reproduction in plants, sexual reproduction in humans, sex hormones in humans, sexually transmitted infections, chromosomes, genes and proteins, mitosis, meiosis, monohybrid inheritance, variation, adaptive features, selection, energy flow, food chains and webs, nutrient cycles, population, community, ecosystem, population-growth phases, food supply, habitat destruction, pollution, conservation, biotechnology and genetic modification. 61 of 61 syllabus sections have linked teaching and staged practice. The earlier inheritance overview remains introductory, and the monohybrid pathway develops the relevant Core and Supplement requirements. This is not full programme completion or guaranteed exam readiness. Written practice is self-checked.

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Original teaching content and links to official sources. Check your exam year and qualification before using a resource.