AQA GCSE Combined Science: Trilogy Biology Paper 1 (Higher), 2022: Question 5

✅ Correct answers

• Similarities: both are made of abnormal cells.
• Both result from changes in the cell’s DNA / genes, often caused by mutations.
• Both can form a lump or mass of cells.
• Differences: malignant tumours are cancerous; benign tumours are not.
• Malignant tumours usually grow faster.
• Malignant tumours invade nearby tissues and can spread to other parts of the body.
• Benign tumours stay in one place and do not spread.
• Malignant tumours can form secondary tumours; benign tumours do not.

💡 Key knowledge

• A tumour is a mass of abnormal cells.
• Malignant means cancerous and dangerous because it can spread.
• Benign means non-cancerous and usually less harmful because it stays localised.
• Examiner note: credit is given for any four correct points, but you need at least one similarity and one difference for a strong answer.

🧠 Exam technique

• Use compare language: both , whereas , but , however .
• Write short, precise statements: one mark is often one correct fact.
• Top responses usually mention spread, growth rate, and cancerous / non-cancerous.

❌ Common errors

• Only saying “malignant is worse” without explaining why.
• Confusing benign with malignant.
• Writing about symptoms or treatment instead of the tumour features.
• Missing the key idea that malignant tumours can spread.

✅ Correct answers

• There is little exposure to ionising radiation / UV light / sunlight.
• There is little exposure to carcinogens such as smoking or other harmful substances.
• So there is less cell / DNA / gene damage and fewer mutations.
• Skin cancer takes a long time to develop, so it is less likely in young people.

💡 Key knowledge

• UV light can damage DNA in skin cells.
• Cancer develops after mutations build up over time.
• Young children generally have had less time for damaging exposure to happen.

🧠 Exam technique

• Link cause and effect: less UV → less DNA damage → fewer mutations → fewer cancers .
• For 2 marks, give the exposure reason and the DNA damage reason.

❌ Common errors

• Saying only “children don’t get cancer” — this is too vague.
• Talking about inherited traits without linking to the mark scheme.
• Not mentioning UV, carcinogens, or mutations.

✅ Correct answers

• The number of new cases increases with age up to about 65–69 years.
• The greatest number of new cases is in the 65–69 age group.
• After about 65–69 years, the number of new cases decreases.
• Females have more new cases than males up to about age 59, but males have more from about age 60 onwards.

💡 Key knowledge

• “Conclusion” means a statement based on the data.
• Use the bars in Figure 10 for new cases, not the lines for rate per 100 000.

🧠 Exam technique

• Use the graph to identify a clear pattern, then quote an age range.
• Two separate conclusions are needed for 2 marks.
• Good answers describe both the increase and the peak / later decrease.

❌ Common errors

• Describing the wrong set of data, e.g. using the per-100 000 lines instead of the number of new cases.
• Only saying “it goes up” without giving a useful age range.
• Repeating the same idea twice in different words.

✅ Correct answer

• To account for the different group sizes of males and females / different age groups.
• This makes the data comparable between groups.
• It also allows comparison with populations in other places / countries.

💡 Key knowledge

• Rates per 100 000 are used to compare risk fairly.
• Total numbers can be misleading if one group is much larger than another.

🧠 Exam technique

• Use the phrase so different group sizes can be compared .
• For 1 mark, a short answer is enough if it clearly says “to compare groups fairly”.

❌ Common errors

• Saying “because totals are not accurate” — too vague.
• Writing about percentages instead of explaining why a rate is needed.

✅ Correct answers

• The number of people with skin cancer per 100 000 increases with age.
• In females, the rate increases at a steady rate.
• In males, the rate increases at a similar or slightly lower rate up to about 55–59 years.
• After about 59, the rate in males increases more rapidly than in females.

💡 Key knowledge

• Read the lines on the graph, not the bars.
• The dashed line is males; the solid line is females.
• “Trend” means how the data changes overall.

🧠 Exam technique

• One mark = one correct trend statement.
• Use age intervals and comparative language to score full marks.
• If asked for two trends, make sure they are different.

❌ Common errors

• Describing the number of new cases instead of the rate per 100 000.
• Mixing up males and females.
• Giving vague comments like “they both go up a lot”.

📐 Calculations — step by step

1. From Figure 10, the male rate for age 80–84 is 116 per 100 000.
2. Population of males aged 80–84 = 694 000.
3. Use the rate formula:
   number with skin cancer = rate × population ÷ 100 000
4. Substitute the values:
   116 × 694 000 ÷ 100 000
5. Calculate:
   = 805.04
6. Round to 3 significant figures:
   805

✅ Correct answer

Number of males with skin cancer = 805 (3 s.f.)

• Marks are available for:
  • using the correct rate
  • correct substitution into the formula
  • correct final answer rounded to 3 significant figures

🧠 Exam technique

• Always show the formula and workings.
• Keep units and population size clear: rate is per 100 000.
• Remember to round only at the end.

❌ Common calculation traps

• Forgetting to divide by 100 000.
• Using the wrong value from the graph.
• Rounding too early.
• Giving 805.04 instead of the required 805 to 3 s.f.
• Answering with no method, which can lose method marks.

💡 What top answers do well

• Use clear compare language for tumours.
• Link UV / carcinogens to DNA damage and mutations.
• Read the correct part of the graph for each question.
• Use “per 100 000” to compare fairly.
• Show a correct calculation with rounding to 3 s.f.

🧠 Final exam reminder

• Short, precise answers usually score best.
• For graph questions, always mention the age group.
• For calculations, write the method even if the final answer is simple.