Biology 0610 · IGCSE · Gas exchange in humans

Gas exchange in humans — practice question

Fig. 6.1 shows one section of a bronchiole from the lungs of a person who has never smoked cigarettes (non-smoker) and one section of a bronchiole from a person who has smoked cigarettes for several years (smoker). The two sections were taken from the same relative position in the lungs and are drawn to the same scale.
(a(i))[3]

Complete Table 6.1 by using Fig. 6.1.

(a(ii))[2]

State two other differences between the bronchiole of a non-smoker and that of a smoker.

(b)[2]

Explain, using evidence from Fig. 6.1, why the smoker has a higher risk of lung infections than a non-smoker.

(c)[2]

State the names of two substances in tobacco smoke that are harmful.

Worked solution & mark scheme

This 9-mark question has a full step-by-step worked solution and mark scheme. One marking point: non-smoker: many/long cilia, broad air space, thin mucus spread evenly; smoker: few/short cilia, narrow air space, thick mucus spread unevenly (any three contrasts)

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