Explain how smoking cigarettes increases a person's risk of developing lung cancer.

Eduqas GCSE Biology — 3.4 Non-communicable diseases in humans · Explain · 4 marks · View as Markdown

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

Model answer (4 marks)

Cigarette smoke contains carcinogens that damage the DNA of lung cells.
These carcinogens cause mutations in the genes that control cell growth.
The mutations lead to uncontrolled, rapid cell division.
Uncontrolled division results in the formation of a lung tumour, i.e. cancer.

Examiner tips

  • Use the exact terms: carcinogens, DNA mutations, uncontrolled cell division, tumour.
  • Show the causal chain from smoke to tumour.
  • Keep each point brief and to the point.
  • Use correct UK spelling (e.g., tumour).

Common mistakes

  • Confusing ‘carcinogens’ with ‘tobacco’ or ‘nicotine’ only.
  • Failing to mention DNA mutations or uncontrolled cell division.
  • Using vague language such as ‘bad chemicals’ instead of ‘carcinogens’.

Mark scheme (4 marks)

  1. Cigarette smoke contains carcinogens / cancer-causing chemicals / mutagens
  2. Carcinogens cause mutations in the DNA of lung cells
  3. Mutations cause cells to divide uncontrollably / out of control
  4. This uncontrolled cell division leads to the formation of a tumour / cancer

Related

More Non-communicable diseases in humans questions

▶ Try answering this question with AI marking (free) →