OCR GCSE Biology A: Health, disease types and the spread and prevention of communicable disease (J247) – Practice Questions

These are original questions written for Marlbridge, for revision and practice on this content. They are not reproduced past-paper questions, and they do not replicate the exam’s exact structure, question count or mark tariffs – examination boards hold copyright in their own papers. Use these alongside the official past papers from your board or school.

These questions follow the OCR GCSE (9-1) Gateway Science Biology A (J247) specification, Version 4.0 (August 2026), statements B6.3a to B6.3e in Topic B6. None of these statements is bold, so every question suits both Foundation and Higher Tier. Learn the content first from the study guide and the revision notes. Course pages: OCR GCSE Biology hub and checklist.

Questions

1. Describe the relationship between health and disease. [3]

2. State whether each condition is communicable or non-communicable. [5] Scurvy; athlete’s foot; cystic fibrosis; malaria; a cancer of the lung.

3. (a) Explain why a person infected with HIV is more likely to develop tuberculosis. [3] (b) Describe how infection with HPV is linked to cervical cancer. [3]

4. Influenza spreads quickly through a school. (a) Explain why the virus spreads so easily there. [2] (b) Suggest two ways the school could reduce the spread. [2]

5. A culture begins with 25 bacteria. Each bacterium divides every 20 minutes. (a) Calculate the number of bacteria after 3 hours, assuming every cell keeps dividing. [3] (b) Write your answer to part (a) in standard form. [1] (c) Suggest one reason why the real number would be lower. [1]

6. A town has 8500 residents. A random sample of 250 residents is tested for a pathogen and 38 test positive. (a) Estimate the number of infected residents in the town. [3] (b) Explain why the sample should be random. [1] (c) Suggest how the estimate could be made more reliable. [1]

7. Town P has 21 000 people. It recorded 63 new cases of a disease in a year. After a hygiene campaign it recorded 45. (a) Calculate the incidence before the campaign, in cases per 100 000 people. [2] (b) Calculate the percentage decrease in the number of cases. Give your answer to 1 decimal place. [2] (c) Explain why incidence is better than the number of cases for comparing two towns. [1]

8. A clinic counted mosquitoes caught in traps each month and the number of malaria cases that month.

Mosquitoes caught	12	25	31	44	52	60	75	88
Malaria cases	4	9	8	15	19	18	27	31

(a) Describe the correlation shown by the data, quoting figures. [2] (b) Explain why the data alone do not prove that more mosquitoes cause more cases. [2] (c) Suggest one way to reduce mosquito numbers. [1]

9. A gardener sees mosaic-patterned leaves on tomato plants and suspects a viral disease. (a) Describe two ways a fungal disease could spread between plants in a greenhouse. [2] (b) Name two methods, other than looking at the leaves, that could detect the pathogen. [2] (c) Give two reasons why visual identification alone may be unreliable. [2]

10. Three hospital wards recorded infections per 1000 patient-days for six months before and after changes.

Ward	Change made	Before	After
A	Alcohol gel at every bed and staff reminders	8.4	5.1
B	Staff given a leaflet only	7.9	7.2
C	No change	8.1	7.9

(a) Calculate the percentage decrease for ward A. Give your answer to 1 decimal place. [2] (b) Use the data to evaluate which change was most effective. [2] (c) Suggest two reasons why the comparison between wards may not be fair. [2] (d) Explain how alcohol gel helps break the route of spread. [2]

11. A grower tested treatments against a fungal leaf disease. Each treatment used 100 plants. The table shows the number infected after six weeks.

Treatment	Plants infected
None	64
Fungicide spray	21
Wider spacing	38
Spray and wider spacing	9

(a) Calculate the percentage reduction in infection produced by the spray alone. Give your answer to 3 significant figures. [2] (b) Calculate the percentage reduction for the combined treatment. Give your answer to the nearest whole number. [2] (c) Explain how wider spacing reduces the spread of a disease carried by spores. [2] (d) Evaluate whether the grower should use the spray on every crop. [3]

Answers

1. Health is a state of physical, mental and social wellbeing, not just the absence of disease [1]. Disease can reduce health in one or more of these areas [1]. Poor health, for example from a poor diet, can make disease more likely [1]. [3] Examiner insight: Answers usually gain credit for naming all three parts of health and for showing the link runs both ways; “health means not ill” alone does not describe a relationship.

2. Scurvy: non-communicable [1]. Athlete’s foot: communicable [1]. Cystic fibrosis: non-communicable [1]. Malaria: communicable [1]. Lung cancer: non-communicable [1]. [5] Examiner insight: Each item is judged separately, so a pattern guess loses credit; cystic fibrosis is inherited but still not communicable, and cancer is not caught.

3. (a) HIV damages the immune system [1]. The body is less able to destroy TB bacteria [1]. So TB infection is more likely to take hold or become active [1]. [3] (b) HPV is a virus that infects cells of the cervix [1]. Long-lasting infection with some types changes the cells [1]. They divide uncontrollably and form a tumour; the cancer is not itself communicable [1]. [3] Examiner insight: Answers gain credit by showing the direction of effect and the mechanism; “HIV causes TB” or “HPV is cancer” are the usual wrong turns.

4. (a) Pupils are close together so droplets from coughs and sneezes reach many people [1]. Shared surfaces and hands also pass the virus on [1]. [2] (b) Any two from: cover coughs and sneezes, wash hands, ventilate rooms, keep ill pupils at home [1] [1]. [2] Examiner insight: “Crowded” alone is weak; answers earn the mark when the crowding is linked to the route of transmission.

5. (a) 3 hours = 180 minutes, so 9 divisions [1]. 25 × 2⁹ = 25 × 512 [1]. 12 800 bacteria [1]. [3] (b) 1.28 × 10⁴ [1]. (c) Nutrients or space run out, or the body’s defences kill some cells [1]. Examiner insight: Showing the number of divisions first makes the working easy to follow; a standard-form answer needs a number between 1 and 10 multiplied by a power of ten.

6. (a) Proportion = 38 ÷ 250 = 0.152 [1]. 0.152 × 8500 [1]. 1292 infected [1]. [3] (b) A random sample is not biased towards people with symptoms, so it represents the whole town [1]. (c) Test a larger sample (or repeat with several random samples) [1]. Examiner insight: State that this is an estimate; “random” earns credit when tied to avoiding bias, not just repeated as a word.

7. (a) 63 ÷ 21 000 × 100 000 [1]. 300 per 100 000 [1]. [2] (b) (63 − 45) ÷ 63 × 100 [1]. 28.6% decrease [1]. [2] (c) It allows for different population sizes [1]. Examiner insight: Give a unit with incidence and say “decrease”; a percentage change needs the original value as the divisor.

8. (a) Positive correlation [1], for example 12 mosquitoes with 4 cases and 88 mosquitoes with 31 cases (strong, points close to a line) [1]. [2] (b) Correlation shows an association only [1]. Another factor, such as rainfall or season, could raise both mosquito numbers and cases [1]. [2] (c) Drain standing water, or use insecticide on breeding sites [1]. Examiner insight: Quoting two data points shows you read the table; avoid “proves” when only a correlation is given.

9. (a) Wind-blown spores [1]. Water splash, or contact on hands and tools [1]. [2] (b) Antigen test [1]. DNA testing [1]. [2] (c) Different problems can cause similar symptoms [1]. Infected plants may show no symptoms early on [1]. [2] Examiner insight: Two distinct points are needed where two are asked for; rewording the same idea gains nothing.

10. (a) 8.4 − 5.1 = 3.3 [1]. 3.3 ÷ 8.4 × 100 = 39.3% [1]. [2] (b) Ward A fell by 39.3%, ward B by 8.9% and control ward C by 2.5% [1]. So alcohol gel with reminders was most effective [1]. [2] (c) Wards may differ in patient illness or size [1]. Other changes, such as staffing or season, may have affected infections [1]. [2] (d) Gel kills pathogens on hands [1]. This stops contact passing them to patients [1]. [2] Examiner insight: Comparing percentages, not raw changes, and using the control ward as a baseline are what turn a statement into evaluation.

11. (a) (64 − 21) ÷ 64 × 100 [1]. 67.2% [1]. [2] (b) (64 − 9) ÷ 64 × 100 [1]. 86% [1]. [2] (c) Spores must travel further between plants [1]. Fewer reach a leaf, and leaves are less likely to touch [1]. [2] (d) Spray cut infection by about two thirds, and combining gave the lowest infection [1]. Limits: spray does not remove all infection, costs money, and may harm other organisms or lead to resistant fungi [1]. Judgement: use it where disease risk is high, together with spacing and removing infected plants, not blindly on every crop [1]. [3] Examiner insight: Evaluation answers gain credit when a benefit, a limit and a clear judgement all appear, with at least one figure quoted.

Where marks are usually lost

• Describing health as only physical.
• Labelling cancer, scurvy or cystic fibrosis as communicable.
• Writing “HIV causes TB” instead of explaining the weakened immune system.
• Treating the vector as the pathogen.
• Giving a control method that does not match the route.
• Dropping units or “per 100 000” from incidence.
• Using the new value, not the original, as the divisor for percentage change.
• Calling an estimate from a sample an exact figure.
• Claiming that a correlation proves cause.

Next steps

• Revise with the revision notes and re-read the study guide.
• Tick off statements on the printable checklist and see the OCR GCSE Biology hub.
• Try the free 10-minute diagnostics to check other topics.
• Book a free trial class for help from a teacher.

Official syllabus

OCR GCSE (9-1) Gateway Science Biology A (J247), Version 4.0 (August 2026), for first assessment in 2018, published by OCR. Statements B6.3a to B6.3e.