Practise 36 exam-style questions on Discovery and development of drugs for AQA GCSE Biology. Write your answer as you would in the exam and get it marked in seconds against the mark scheme, point by point, with an AI tutor on hand if you get stuck.
36 questions
1–4 marks each
Instant marking
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20 questions, marked as you go
Sample questions with model answers
Here are 4 of the questions in this topic, each with a model answer, an explanation of why it earns the marks and the mark scheme an examiner would use.
Question 1
2 marks
Explain what is meant by a double-blind trial and why a placebo is used.
Model answer
A double-blind trial is when neither patients nor doctors know which treatment the patient receives. A placebo is an inactive treatment used so effects can be compared and to reduce bias/placebo effect.
Explanation
Blinding prevents conscious or unconscious bias; placebos allow distinguishing real drug effects from psychological/placebo responses.
Mark scheme
1 mark
Double-blind: neither patient nor clinician knows who gets real drug or placebo
Accept wording about both investigators and subjects being blind.
1 mark
Placebo used to compare real drug effect and control for placebo effect / reduce bias
Award for recognising placebo is inactive and used as control.
Question 2
2 marks
What is pharmacokinetics and why is it important when establishing dose schedules?
Model answer
Pharmacokinetics is how the body absorbs, distributes, metabolises and excretes a drug. It informs dosing intervals and amounts to maintain effective concentrations without toxicity.
Explanation
Understanding how drug levels change over time determines how much and how often to give a drug to be effective and safe.
Important for dose schedules to maintain therapeutic levels and avoid toxicity
Award for linking PK to dosing decisions.
Question 3
3 marks
Explain why many new drugs are now synthesised by chemists rather than being extracted from plants.
Model answer
Synthesis allows production of large amounts, modification to improve efficacy and reduce side effects, and consistent purity and supply without relying on plant sources.
Explanation
Synthetic production ensures reliable, scalable, and optimisable drug supply with consistent purity and allows chemical modifications to improve therapy.
Mark scheme
1 mark
Allows mass production (large-scale manufacture)
Accept consistent supply.
1 mark
Chemists can modify molecules to improve efficacy / reduce toxicity
Allow improved pharmacokinetics.
1 mark
Gives consistent purity and quality compared with plant extracts
Award for removing dependence on plant availability/seasonality.
Question 4
3 marks
Explain two advantages and one limitation of using antibiotics produced from microorganisms versus chemically synthesised antibiotics.
Model answer
Advantages: many natural antibiotics have novel mechanisms and evolved specificity; can be starting point for modification. Limitation: natural sources may yield supply or variability issues and resistance can develop.
Explanation
Microbial antibiotics provide powerful natural scaffolds but face supply and resistance challenges; chemical synthesis offers scalability and modification potential.
Mark scheme
1 mark
Advantage: natural antibiotics may have novel mechanisms or high potency
Award for novel action or high activity.
1 mark
Advantage: can be chemically modified to improve properties (synthetic derivatives)
Award for lead-compound concept.
1 mark
Limitation: supply variability or scalability and potential for resistance development
Award for supply or resistance issues.
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