1. 1
   A school nurse explains to a health class that people take many different substances, from prescribed medicines to over-the-counter tablets, and discusses what makes a substance count as a drug.

   (a)

   Which of the following is the best definition of a drug?

   [1 mark]

   • AAny substance taken into the body that modifies or affects chemical reactions in the body
   • BAny substance that a person eats for energy
   • CAny liquid a person drinks to stay hydrated
   • DAny substance produced naturally within a healthy body

   (b)

   Which of these is an example of a drug, according to the definition given?

   [1 mark]

   • AWater drunk to quench thirst
   • BAn antibiotic tablet taken to treat an infection
   • CAir breathed in during normal breathing
   • DStarch digested during a meal

   (c)

   A student argues that the water they drink each day should also count as a drug. Using the definition of a drug, explain whether the student is correct.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   A pharmacist compares two customers: one with a common cold, caused by a virus, and one with a bacterial ear infection, to decide whether an antibiotic would help either of them.

   (a)

   Antibiotics are effective against which type of pathogen?

   [1 mark]

   • AViruses
   • BFungi only
   • CBacteria
   • DAll pathogens equally

   (b)

   Which statement about antibiotics and viruses is correct?

   [1 mark]

   • AAntibiotics kill viruses just as effectively as bacteria
   • BAntibiotics only work on viruses, not bacteria
   • CAntibiotics turn viruses into harmless bacteria
   • DAntibiotics have no effect on viruses

   (c)

   Explain why the pharmacist would not recommend an antibiotic for the customer with the common cold.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   In a hospital laboratory, a sample of bacteria taken from a wound is grown on a dish alongside discs soaked in different antibiotics, to see which antibiotics stop the bacteria growing and which do not.

   (a)

   One antibiotic disc has almost no effect on the bacteria growing near it, while most of the others clearly stop bacterial growth nearby. Suggest why this one antibiotic has little effect, and explain what this means for a patient being treated with it.

   [3 marks]

   (b)

   Explain how repeated use of antibiotics in a hospital could lead to a larger proportion of the bacteria present there becoming resistant over time.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   A newly qualified doctor is being trained on hospital prescribing policy, which limits antibiotics to cases where they are essential, rather than prescribing them for every patient who requests them.

   (a)

   Explain, step by step, how prescribing antibiotics only when they are essential can help to limit the development of antibiotic-resistant bacteria such as MRSA.

   [6 marks]

   (b)

   Explain what problems would arise for patients and hospitals if antibiotic-resistant bacteria such as MRSA became widespread, and suggest why finding new antibiotics is not a simple long-term solution to this problem.

   [6 marks]

   Total for question 4: 12 marks

5. 5
   A veterinary surgeon treats a cow with a bacterial infection and also gives a separate cow a painkiller for a leg injury, and explains to a farming student how both are examples of drugs.

   (a)

   Why does a painkiller given to the cow with the leg injury count as a drug?

   [1 mark]

   • ABecause it is a substance taken into the body that modifies or affects chemical reactions in the body
   • BBecause it provides energy for the cow to heal
   • CBecause it is a natural part of the cow's diet
   • DBecause it is used only by veterinary surgeons

   (b)

   Which of these best describes why an antibiotic given to the cow with the bacterial infection would not help the cow with the leg injury?

   [1 mark]

   • AAntibiotics remove all pain regardless of its cause
   • BAntibiotics only affect chemical reactions related to bacterial infections, not pain from an injury
   • CAntibiotics only work on animals, not on injuries
   • DAntibiotics are not classed as drugs

   (c)

   Explain why both the painkiller and the antibiotic can correctly be described as drugs, even though they are used to treat very different problems.

   [2 marks]

   Total for question 5: 4 marks

6. 6
   A student compares a painkiller, which relieves the symptom of pain without treating its underlying cause, with an antibiotic prescribed for a bacterial chest infection, which treats the cause of the illness.

   (a)

   Which statement correctly distinguishes the two types of drug described?

   [1 mark]

   • AThe painkiller kills the bacteria causing the infection, while the antibiotic only masks the pain
   • BNeither drug affects the body's chemical reactions
   • CThe painkiller relieves a symptom, while the antibiotic treats the underlying bacterial cause of the illness
   • DBoth drugs work by killing the pathogen responsible for the illness

   (b)

   Which type of pathogen would the antibiotic prescribed for the chest infection be effective against?

   [1 mark]

   • AViruses only
   • BFungi only
   • CAll pathogens
   • DBacteria

   (c)

   Explain why simply relieving the pain caused by a bacterial chest infection, without also taking an antibiotic, would not clear the underlying infection.

   [2 marks]

   Total for question 6: 4 marks

7. 7
   A microbiology student repeats the antibiotic disc experiment on a fresh sample of bacteria taken several months later from the same hospital ward, and finds that one antibiotic which previously stopped almost all bacterial growth nearby now has almost no effect.

   (a)

   Suggest and explain what has most likely happened to the bacteria on the ward between the two experiments.

   [3 marks]

   (b)

   Explain what steps the hospital could now take, having found this result, to help limit any further spread of resistance to this antibiotic.

   [4 marks]

   Total for question 7: 7 marks

8. 8
   A pharmaceutical researcher is explaining to trainee scientists why developing new antibiotics is a continual and urgent challenge, rather than something that only needs to be done once.

   (a)

   Explain why bacteria are able to become resistant to an antibiotic even though the antibiotic was originally effective against them, and why this means new antibiotics may eventually need to be developed.

   [6 marks]

   (b)

   Explain what actions, beyond simply developing new antibiotics, could help to slow down the rate at which bacteria become resistant to the antibiotics already available.

   [6 marks]

   Total for question 8: 12 marks

End of questions