Question 1
Which statement describes a drug?
- A substance that provides energy for respiration
- Any substance taken into the body that modifies or affects chemical reactions in the body
- A substance that kills all microorganisms outside the body
- Any substance made by the body to fight disease
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Answer: B (1)
Question 2
A patient has influenza, which is caused by a virus. Why would a doctor not prescribe an antibiotic?
- Antibiotics do not affect viruses
- Antibiotics kill only fungi
- Viruses are too small to be seen
- Antibiotics cause influenza to spread
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Answer: A (1)
Question 3
Penicillin is an antibiotic. (a) State the type of infection that penicillin is used to treat. [1] (b) State what penicillin does to the pathogen. [1] (c) State one type of pathogen that penicillin does not affect. [1]
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- (a) bacterial (infection) (1)
- (b) kills (the) bacteria (1) allow kills the pathogen
- (c) viruses (1)
Question 4
A doctor treats a patient with an antibiotic, but the infection does not improve. Suggest what has happened to the bacteria.
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- the bacteria are resistant to the antibiotic (1)
- so the antibiotic does not kill them / is less effective (1) reject 'the patient is resistant / immune'
Question 5
A student says: 'Antibiotics are drugs that cure all infections.' (a) State why the statement is incorrect for infections caused by viruses. [1] (b) Describe what is meant by the term drug. [2] (c) State what is meant by bacteria being resistant to an antibiotic. [1]
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- (a) antibiotics do not affect / kill viruses (1)
- (b) (any) substance taken into the body (1)
- that modifies or affects chemical reactions in the body (1)
- (c) the antibiotic does not kill the bacteria / is less effective against them (1) reject 'the person is resistant'
Question 6
Supplement (what this means)
Supplement: only for the Extended papers (2 and 4). Core students can skip it. What the labels meanMRSA is a bacterium that is resistant to many antibiotics. Explain why a doctor should prescribe an antibiotic only when it is essential.
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- (using antibiotics less gives) fewer chances for resistant bacteria to survive and reproduce (1)
- so resistant bacteria such as MRSA are less likely to develop / spread, or antibiotics stay effective (1) reject 'the body becomes resistant'
Question 7
Supplement (what this means)
Supplement: only for the Extended papers (2 and 4). Core students can skip it. What the labels meanA population of bacteria contains a few resistant bacteria. A patient is treated with an antibiotic many times, including for minor infections. (a) Explain how the repeated use of the antibiotic increases the number of resistant bacteria. [4] (b) Suggest one way to reduce the spread of resistant bacteria. [1]
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- (a) resistance arose by mutation (1)
- the antibiotic kills the non-resistant bacteria (1)
- the resistant bacteria are not killed / survive (1)
- the resistant bacteria reproduce (1)
- and pass on the resistance, so the number of resistant bacteria rises (1)
- Max 4 for (a)
- (b) use antibiotics only when essential / not for viral or minor infections (1)