AQA GCSE Combined Science Foundation (8464), Foundation tier · Biology › Infection and response › Communicable diseases
Practise Antibiotics and painkillers. 7 exam-style questions on this subtopic, at up to four difficulty levels, with full mark schemes and a progress tracker. Free, no account needed.
What antibiotics and painkillers can and cannot do, why antibiotics do not work on viruses, why it is hard to make drugs that kill viruses and why antibiotic-resistant bacteria are a concern. Questions are usually short 'explain why' items, sometimes with data.
Key facts
Antibiotics kill bacteria inside the body, e.g. penicillin
Antibiotics do NOT kill viruses
Use the specific antibiotic for the specific bacterium
Painkillers treat symptoms but do not kill pathogens
Resistant strain = bacteria that are not killed by an antibiotic
Drugs that kill viruses are hard to develop: viruses are inside cells, so the drugs may damage body tissues
Notes
Antibiotics
Antibiotics, such as penicillin, are medicines that cure bacterial diseases by killing infective bacteria inside the body.
Specific bacteria should be treated with specific antibiotics: an antibiotic that kills one type of bacterium may not kill another.
Antibiotics have greatly reduced deaths from infectious bacterial diseases.
Antibiotics cannot kill viruses, so they do not help with viral diseases such as colds, flu or measles.
Antibiotic resistance
diagram
Some strains of bacteria have become resistant to antibiotics: the antibiotic no longer kills them. This is of great concern.
The antibiotic kills the non-resistant bacteria, so the resistant ones survive and multiply.
Infections caused by resistant strains are hard to treat and can spread, e.g. MRSA and some strains of the bacterium that causes gonorrhoea.
To slow the development of resistance, doctors should not prescribe antibiotics for viral or minor infections, and patients should complete the course of antibiotics.
Painkillers and other medicines
Painkillers (e.g. aspirin, paracetamol) and other medicines, such as cough medicines, treat the symptoms of a disease.
They do not kill pathogens, so they do not cure the disease. The immune system still has to destroy the pathogen.
Why viral diseases are hard to treat
Viruses live and reproduce inside the body's cells.
It is difficult to develop drugs that kill viruses without also damaging the body's tissues.
So most viral diseases are treated with painkillers and other medicines to ease the symptoms while the immune system destroys the virus. A few drugs can control viruses, e.g. antiretroviral drugs for HIV.
How to answer each type of question
Explain why antibiotics are not prescribed
2 marksGrade 4
Say what type of pathogen causes the disease.
Say that antibiotics do not kill that type of pathogen (viruses).
Example. A patient with a cold asks for antibiotics. The doctor refuses. Explain why.
Show the model answerHide the model answer
Colds are caused by a virus (1). Antibiotics do not kill viruses, so they would not help (1).
Compare painkillers and antibiotics
2 marksGrade 4
Painkillers: relieve symptoms, do not kill pathogens.
Antibiotics: kill the bacteria, so they cure the disease.
Example. A person with a bacterial throat infection takes painkillers and a course of antibiotics. Describe the different effect of each type of medicine.
Show the model answerHide the model answer
Painkillers relieve the symptoms, such as pain, but do not kill the bacteria (1). Antibiotics kill the bacteria causing the infection, so they cure it (1).
Don’t lose marks
Saying antibiotics kill viruses or cure colds and flu.
Saying painkillers cure a disease or kill pathogens.
Saying the person, or their body, becomes resistant to antibiotics. It is the bacteria that become resistant.
Mixing up antibiotics (medicines) and antibodies (made by white blood cells).
Answering 'why are antiviral drugs hard to develop?' with 'antibiotics don't work on viruses'. The reason is that viruses are inside body cells, so drugs that kill them may damage body tissues.
More tips
Memory tricks
AntiBiotics are anti-Bacteria. They do nothing to viruses.
Painkillers kill pain, not pathogens.
Three 'anti' words: antibiotic (medicine, kills bacteria), antibody (made by white blood cells, binds to antigens), antitoxin (neutralises toxins).
Exam technique
Check which type of pathogen causes the disease in the question before you recommend a treatment.
Use 'resistant' for bacteria and 'immune' for people. 'The bacteria become immune' does not get the mark.
In percentage change calculations, divide by the original value and show your working.
What each grade needs
What you need to be able to do, from the first marks up to the top grade.
Grade 3
State what antibiotics doAntibiotics, such as penicillin, kill infective bacteria inside the body, curing bacterial diseases.
Grade 3
State what painkillers doPainkillers treat the symptoms of a disease but do not kill pathogens.
Explain why specific antibiotics are neededDifferent antibiotics kill different bacteria, so the antibiotic must match the bacterium causing the disease.
Quick recall
Cover the answers and test yourself. The app has these as flashcards that come back just before you'd forget them.
Doctors use different types of medicine to treat diseases. Name one antibiotic.
Penicillin
Antibiotics and painkillers are both used to treat illness, but they work in very different ways. Give one example of a painkiller.
Paracetamol (or ibuprofen / aspirin)
Sample questions
Written for this site in the style of AQA exam questions. They are not taken from real past papers.
Question 1Easy5 marks
Doctors use different types of medicine to treat diseases.
(a) What do antibiotics do? Tick (✓) one box.[1]
Kill bacteria inside the body
Kill viruses inside the body
Make the body produce antibodies
Reduce pain but do not kill pathogens
(b) Name one antibiotic.[1]
(c) Many people with a cold take painkillers, such as paracetamol. Explain why painkillers do not cure a cold.[2]
(d) Give the reason why doctors do not prescribe antibiotics for a cold.[1]
Show the answer and mark scheme
(a)Answer: Kill bacteria inside the body
(b)Answer: Penicillin
penicillin
(c)
painkillers only treat the symptoms
(they) do not kill the pathogen / virus
(d)
colds are caused by viruses and antibiotics do not kill viruses
Question 2Medium7 marks
A patient has a throat infection caused by a bacterium. A doctor prescribes an antibiotic and tells the patient to take a painkiller as well.
(a) Explain why the doctor must choose an antibiotic that is effective against the specific bacterium causing the infection.[2]
(b) Explain the different roles of the antibiotic and the painkiller in treating the patient.[2]
(c) The use of antibiotics has greatly reduced deaths from bacterial diseases. Give one reason why scientists are concerned about the future use of antibiotics.[1]
(d) It is difficult to develop drugs that kill viruses. Explain why.[2]
Show the answer and mark scheme
(a)
different antibiotics kill different types of bacteria / specific bacteria must be treated with specific antibiotics
(otherwise) the bacteria would not be killed and the infection would not be cured
(b)
the antibiotic kills the bacteria (causing the infection)
the painkiller relieves the symptoms / pain but does not kill the bacteria
(c)
strains of bacteria resistant to antibiotics are emerging / becoming more common
(d)
viruses live / reproduce inside the body’s cells
(so) drugs that kill viruses may also damage the body’s cells / tissues