Biology 9700 · AS & A Level · The gas exchange system

The gas exchange system — practice question

Which flow diagram correctly shows the impact of tar entering the lungs?

  • Acarcinogens come into contact with DNA $\rightarrow$ mutation occurs $\rightarrow$ uncontrolled cell division $\rightarrow$ mass of cells produced
  • Bgoblet cells secrete more mucus $\rightarrow$ mucus accumulates causing infection $\rightarrow$ phagocytes attracted by inflammation $\rightarrow$ causes irritation and coughing
  • Cgoblet cells secrete more mucus $\rightarrow$ mutation occurs $\rightarrow$ phagocytes attracted by inflammation $\rightarrow$ mass of cells produced
  • Dphagocytes attracted by inflammation $\rightarrow$ mutation occurs $\rightarrow$ uncontrolled cell division $\rightarrow$ elastase destroys the alveolar walls

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