Biology 9700 · AS & A Level · Transport of oxygen and carbon dioxide

Transport of oxygen and carbon dioxide — practice question

People who smoke tobacco are at a higher risk of developing non-infectious diseases of the gas exchange system and the cardiovascular system. In 2004, a survey was carried out on the most popular filter cigarette brands from each of the six World Health Organization (WHO) regions. During this survey, the smoke drawn through the filter was tested for tar, nicotine and carbon monoxide (CO) content for every cigarette brand. For each WHO region, the mean tar, nicotine and carbon monoxide content of the different cigarette brands was calculated. The results are shown in Fig. 2.1.
(a)[1]

With reference to Fig. 2.1, list the two WHO regions where smokers face the highest risk of developing diseases of the gas exchange or cardiovascular systems.

(b)[2]

With reference to Fig. 2.1, explain why smoking a popular brand of cigarette from the AFRO region is more likely to raise the risk of blood clots forming than smoking a popular brand of cigarette from the EURO region.

(c)[4]

One short-term effect of cigarette smoking is a decrease in the supply of oxygen to body tissues. Describe and explain how cigarette smoking causes the supply of oxygen to body tissues to decrease.

Worked solution & mark scheme

This 7-mark question has a full step-by-step worked solution and mark scheme. One marking point: Eastern Mediterranean and South-East Asia / EMRO and SEARO

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