AQA GCSE Combined Science: Trilogy Biology Paper 1 (Foundation), 2021: Question 2
10 marks · Standard Demand difficulty · Short Answer
Identify antibiotics, symptoms of gonorrhoea, and interpret experimental results on the effectiveness of different antibiotics against bacterial and viral infections.
Practise this questionQuestion
Question text
02 Antibiotics are used to treat bacterial infections.
02.1 Which substance is used as an antibiotic?
[1 mark]
Tick ( ) one box.
Aspirin
Digitalis
Penicillin
Gonorrhoea and chlamydia are two sexually transmitted infections.
Gonorrhoea and chlamydia infections can be treated with antibiotics.
02.2 Give one symptom of gonorrhoea.
[1 mark]
A scientist investigated which antibiotics were most effective at treating gonorrhoea
and chlamydia.
This is the method used.
1. Grow gonorrhoea bacteria in a Petri dish.
2. Prepare four different antibiotic solutions, A, B, C and D, of the same concentration.
3. Cut four filter paper discs to the same size.
4. Soak each paper disc in a different antibiotic solution.
5. Put the four paper discs into the Petri dish.
6. Repeat steps 3 to 5 using a Petri dish with chlamydia bacteria growing in it.
7. Keep both Petri dishes at 25 °C for 3 days.
02.3 Give two control variables used in this investigation.
[2 marks]
Figure 2 shows the results.
A clear area around a paper disc is where the antibiotic has killed the bacteria.
Figure 2
02.4 Which antibiotic did not kill either type of bacterium?
[1 mark]
Tick ( ) one box.
A B C D
02.5 Which antibiotic would be the most effective to treat a person with a
gonorrhoea infection?
[1 mark]
Tick ( ) one box.
A B 11C D
02.6 Which antibiotic would be the most effective to treat a person who had both
gonorrhoea and chlamydia infections?
[1 mark]
Tick ( ) one box.
A B C D
02.7 Antibiotics cannot be used to treat HIV infections.
Suggest one reason why.
[1 mark]
Fungi can cause an infection of the fingernails and toenails.
Fungal nail infections can spread from one person to another person.
02.8 Some people go to nail salons to have their nails shaped and painted.
Suggest one way workers in nail salons can reduce the risk of infections
being spread.
[1 mark]
02.9 Suggest one reason why fungal infection of toenails is more common than fungal
infection of fingernails.
[1 mark]
Mark scheme
Show the mark scheme
AO /
Question Answers Extra information Mark
Spec. Ref.
02.1 penicillin 1 AO1
4.3.1.8
4.3.1.9
02.2 any one from: 1 AO1
• (yellow / green / white / beige) ignore colour of urine 4.3.1.3
discharge from vagina / penis allow yellow / green / white /
beige discharge
• pain on urinating ignore pain unqualified
allow pain in abdomen
allow pain in testes
allow inflammation of foreskin
allow bleeding between periods
allow bleeding after sex
allow fever / nausea / vomiting
02.3 any two from: 2 AO2
• concentration (of antibiotic) 4.3.1.3
• type of disc allow same type of (filter) paper 4.3.1.8
• size of disc
• temperature or kept at 25 °C
• time or kept for 3 days
allow use sterile Petri dish or
use sterile agar
02.4 B 1 AO3
4.3.1.3
4.3.1.8
4.3.1.9
02.5 C 1 AO3
4.3.1.3
4.3.1.8
4.3.1.9
02.6 A 1 AO3
4.3.1.3
4.3.1.8
4.3.1.9
02.7 any one from: 1 AO1
• antibiotics do not destroy allow antibiotics do not kill 4.3.1.2
viruses viruses 4.3.1.8
allow antibiotics only kill
bacteria
allow HIV is a virus
allow HIV is not a bacterium
• viruses are inside cells allow idea that it is difficult to get
the antibiotic to the virus
02.8 any one from: 1 AO2
• disinfect / sterilise tools / allow put tools / scissors / files in
4.3.1.1
scissors / files fungicide
allow washing / cleaning tools 4.3.1.4
• use a new file for each allow use a new tool / scissors
customer for each customer
• do not treat people with a
fungal nail infection
• disinfect hands between
customers
• use new gloves for each ignore gloves / PPE unqualified
customer
allow wear masks
02.9 any one from: allow converse statements 1 AO3
• feet are washed less 4.3.1.1
• feet are in (more) moist allow idea that less air gets to 4.3.1.4
conditions feet
allow idea that feet are wetter /
warmer (inside socks)
• feet are (often) warmer
allow idea of (bare) feet in
contact with the floor
allow idea of sharing footwear
Total 10
How to answer it
Antibiotics, Pathogens and Infection Control
What this question tests
This question assesses your ability to identify types of drugs, recall symptoms of bacterial STIs, identify control variables in a required practical, and interpret experimental data regarding antibiotic effectiveness. It also covers the differences between bacteria, viruses, and fungi.
Drug Types and Symptoms
💡 Key Knowledge
- Penicillin: An antibiotic used to kill bacteria.
- Aspirin: A painkiller (originally from willow).
- Digitalis: A heart drug (originally from foxgloves).
- Gonorrhoea: A bacterial STI.
✅ Correct Answers
- 02.1: Penicillin
- 02.2: Thick yellow/green discharge (from penis or vagina) OR pain on urinating.
🧠 Exam Technique
When asked for a symptom of Gonorrhoea, the examiner is looking for specific clinical signs. Avoid vague answers like "feeling ill" or "pain in the stomach." Stick to the two main symptoms mentioned in the specification.
Experimental Design: Control Variables
Investigating Antibiotic Effectiveness
💡 What is a Control Variable?
A variable that is kept the same throughout the experiment to ensure the results are valid and that any changes observed are only due to the independent variable (the type of antibiotic).
✅ Correct Answers (Any two)
- Concentration of the antibiotic.
- Size of the filter paper discs.
- Temperature (e.g., kept at 25 °C).
- Time (e.g., kept for 3 days).
- Volume of antibiotic solution on the disc.
❌ Common Errors
Do not just list "The Petri dish" or "The antibiotic." You must specify what about them is being controlled, such as the size of the dish or the concentration of the drug.
Interpreting Results (Figure 2)
✅ Correct Answers
- 02.4: Antibiotic B (It has no clear zone in either dish).
- 02.5: Antibiotic C (It has the largest clear zone in the Gonorrhoea dish).
- 02.6: Antibiotic A (It is the only one that shows a clear zone in both the Gonorrhoea and Chlamydia dishes).
🧠 Data Analysis
Always look at the size of the clear zones. In 02.6, even though C is better for Gonorrhoea, it does nothing for Chlamydia. Antibiotic A is the "broad spectrum" choice here because it works against both.
Antibiotics vs Viruses
💡 Key Knowledge
Antibiotics are specifically designed to target bacterial cell walls or metabolic processes. They cannot kill viruses like HIV.
✅ Correct Answers (Any one)
- Antibiotics do not kill viruses.
- Viruses live/reproduce inside body cells (making them hard to reach without damaging the cell).
❌ Misconception Alert
Never say "the virus is immune to antibiotics." Immunity is a biological process in humans. Instead, say the antibiotic is ineffective or that viruses lack the targets (like cell walls) that antibiotics attack.
Fungal Infections
✅ Correct Answers
02.8 (Reducing spread): Sterilise/disinfect tools between customers, use new nail files for each person, or wash hands/wear gloves.
02.9 (Why toenails?): Feet are often in moist or warm conditions (inside socks/shoes) which fungi prefer. Feet may also be washed less often than hands.
🧠 Thinking like an Examiner
For 02.9, think about the environment. Fungi thrive in "warm, damp, dark" places. Shoes provide exactly this environment, whereas hands are usually dry and exposed to light and air.
Topics
Biology · B3: Infection and Response
Question and mark scheme from the AQA GCSE Combined Science: Trilogy examination, Biology Paper 1 (Foundation), 2021. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.