Biology 9700 · AS & A Level · The gas exchange system
The gas exchange system — practice question
Fig. 5.1 displays a slice of lung tissue taken from a smoker. The image magnification is $\times\,\text{(as shown)}$. In smokers, the walls separating the gas exchange structures in the lungs may break down, so the damaged features seen in Fig. 5.1 appear. The feature marked X is one of these damaged structures.
(a(i))[1]
Name the gas exchange structures that are damaged in Fig. 5.1.
(a(ii))[1]
Name the smoking-related disease that produces the damaged feature labelled X in Fig. 5.1.
(b)[3]
Smoking-related diseases may raise the risk of infectious diseases of the gas exchange system. Describe and explain how smoking can raise the risk of these infections.
(c)[2]
After one cigarette, a smoker will inhale between $14$ and $20\,\text{mg}$ of carbon monoxide. Describe the effects of carbon monoxide on haemoglobin.
Worked solution & mark scheme
This 7-mark question has a full step-by-step worked solution and mark scheme. One marking point: “alveoli; singular: alveolus” …