FreeScienceLessons · AQA BiologyCancer — tumours and risk factors
Key facts
What is cancer?
Cancer occurs when cells undergo uncontrolled cell division, forming a tumour.
Benign tumour — grows in one place, does not invade other tissues, does not usually cause problems. Not cancerous.
Malignant tumour — cells invade neighbouring tissue and spread via the blood/lymph to other organs. This spreading is called metastasis. These are cancerous.
Cancer is caused by mutations in genes that control cell division — cells lose the normal controls that stop them dividing.
Having a risk factor does not guarantee cancer — and some people with no risk factors develop cancer.
Exam questions — 3 questions · 11 marks
⚡ Extended questions included. Read the hint. Write in full sentences. AI marks against the AQA mark scheme.
1 markBenign vs malignantAQA 8461 P1 style
What is the key difference between a benign and a malignant tumour?
A Benign tumours are larger than malignant tumours
B Malignant tumours invade neighbouring tissues and can spread to other parts of the body; benign tumours do not
C Benign tumours are caused by viruses; malignant tumours are caused by UV radiation
D Malignant tumours can be treated but benign tumours cannot
1 markCancer developmentAQA 8461 style
Cancer develops when cells undergo uncontrolled division. What causes this?
A Cells run out of nutrients and start dividing to find more
B Mutations in genes that normally control the cell cycle remove the usual controls on cell division
C Cells are infected by bacteria which cause rapid division
D Body temperature rises above the optimum for enzymes controlling cell division
4 marksRisk factor evaluationAQA 8461 P1 Jun 2023 style
The UK government has introduced HPV vaccination for young people. Explain the scientific basis for this vaccination programme in terms of cancer prevention. (4 marks)