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Exam questions · Biology · Culturing Microorganisms and Developing Medicines

Developing New Medicines

  • 6 exam questions
  • 18 marks
  • 9 quick checks
  1. 1 State [1 mark]

    State what is meant by a placebo.

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    Model answer

    A dummy treatment that does not contain the active drug.

    Mark scheme

    • A treatment with no active drug — 1 mark
  2. 2 Name [2 marks]

    Name the two stages of testing that come after the development stage of a new medicine.

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    Model answer

    Preclinical testing and clinical testing (clinical trials).

    Mark scheme

    • Preclinical testing — 1 mark
    • Clinical testing — 1 mark
  3. 3 Explain [3 marks]

    Explain why a new medicine is tested on cells and animals before it is given to humans.

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    Model answer

    To check that it is not toxic, and does not cause harm that would put human volunteers at risk. Cells show whether it works, and animals show effects on a whole body, such as side effects and how it is absorbed.

    Mark scheme

    • Check for toxicity or harm before using humans — 1 mark
    • Cells show whether it works — 1 mark
    • Animals show whole-body effects — 1 mark
  4. 4 Explain [3 marks]

    Explain why clinical trials of a new medicine are double-blind.

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    Model answer

    Neither the patients nor the doctors know who is receiving the drug and who is receiving the placebo. This stops the patients' expectations, and the doctors' opinions, from affecting the results, so the results are fair and unbiased.

    Mark scheme

    • Neither the patients nor the doctors know — 1 mark
    • Prevents the expectations of patients or the opinions of doctors affecting results — 1 mark
    • So the results are unbiased — 1 mark
  5. 5 Calculate [3 marks]

    In a trial, 200 patients took a new drug and 160 of them improved. Of 200 patients who took a placebo, 60 improved. Calculate the percentage who improved in each group, and the difference between them.

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    Model answer

    Drug group: 160 ÷ 200 × 100 = 80%. Placebo group: 60 ÷ 200 × 100 = 30%. The difference is 50 percentage points.

    Mark scheme

    • 80% — 1 mark
    • 30% — 1 mark
    • 50 percentage points — 1 mark
  6. 6 Evaluate [6 marks]

    Some people think that it is wrong to test medicines on animals. Evaluate the use of animals in the testing of new medicines.

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    Model answer

    Testing on animals can show how a medicine affects a whole living body, including side effects that cells in a dish would not show, so it protects human volunteers from harm. The thalidomide disaster showed what can happen when testing is not thorough. However, animals can suffer pain and distress, and many people think it is wrong to cause this for human benefit. Animals are not the same as humans, so a medicine that is safe in an animal may still be harmful to a person, and the reverse. Scientists therefore use cells, tissues and computer models where possible, and tests on animals are strictly controlled. On balance, until there are alternatives that give the same information, limited and well-regulated testing is justified, to protect people.

    Mark scheme

    • Shows whole-body effects and side effects — 1 mark
    • Protects human volunteers, or example of thalidomide — 1 mark
    • Animals suffer — 1 mark
    • Animals are different to humans, so results may not apply — 1 mark
    • Alternatives such as cells and computer models — 1 mark
    • A reasoned conclusion — 1 mark

Quick check

  1. 1

    Which is the correct order of the stages of developing a medicine?

    1. AClinical testing, discovery, development, preclinical testing
    2. BDiscovery, development, preclinical testing, clinical testing
    3. CPreclinical testing, discovery, clinical testing, development
    4. DDevelopment, discovery, clinical testing, preclinical testing
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    B: Discovery, development, preclinical testing, clinical testing

    Discovery, then development, then preclinical testing, then clinical testing.

  2. 2

    What is preclinical testing?

    1. ATesting on patients
    2. BTesting on volunteers
    3. CTesting on cells, tissues and animals
    4. DTesting after a licence is given
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    C: Testing on cells, tissues and animals

    It is testing in the laboratory, on cells, tissues and animals, before people.

  3. 3

    What is a placebo?

    1. AA treatment with no active drug
    2. BA new drug
    3. CA stronger drug
    4. DA vaccine
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    A: A treatment with no active drug

    A dummy treatment with no active drug.

  4. 4

    Why are clinical trials double-blind?

    1. ATo save money
    2. BTo make the drug work better
    3. CTo speed up the trial
    4. DTo stop bias in the results
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    D: To stop bias in the results

    Neither patients nor doctors know who has the drug, so the results are not biased.

  5. 5

    Who takes part in a phase 1 trial?

    1. AThousands of patients
    2. BA few healthy volunteers
    3. COnly animals
    4. DDoctors only
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    B: A few healthy volunteers

    A few healthy volunteers, to test for safety.

  6. 6

    What is the main aim of a phase 3 trial?

    1. ATo find out whether it is toxic to cells
    2. BTo find the first dose
    3. CTo compare its effectiveness in a large group of patients
    4. DTo design the molecule
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    C: To compare its effectiveness in a large group of patients

    To find out whether it works better than a placebo or existing treatment in many patients.

  7. 7

    In a trial, 40 out of 80 patients improved on a drug. What percentage is this?

    1. A50%
    2. B40%
    3. C80%
    4. D20%
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    A: 50%

    \(40 \div 80 \times 100 = 50\%\).

  8. 8

    Why are new antibiotics needed?

    1. APeople no longer like old antibiotics
    2. BViruses have become bacteria
    3. CAntibiotics are too cheap
    4. DBacteria become resistant to existing antibiotics
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    D: Bacteria become resistant to existing antibiotics

    Bacteria evolve resistance, so older antibiotics stop working.

  9. 9

    In a trial, a group on a placebo showed a 30% improvement. What does this show?

    1. AThe placebo is a drug
    2. BSome patients improve because they expect to, so the placebo group is needed
    3. CThe trial was not fair
    4. DThe patients were not ill
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    B: Some patients improve because they expect to, so the placebo group is needed

    It is the placebo effect, which is why the drug group must be compared with a placebo group.