11.1. Gas exchange in humans
A subsection of Biology, 0610, through 11. Gas exchange in humans
Listing 10 of 291 questions
Table 5.1 shows four functions of the human gas exchange system. Complete Table 5.1 by identifying the part of the human gas exchange system that carries out each function. Table 5.1 function part of the human gas exchange system contracts to decrease air pressure in the lungs allows air to flow between the larynx and the lungs contracts to lower the ribs in forced expiration site of gas exchange Scientists investigated the effect of increasing carbon dioxide concentration in the air on the rate and depth of breathing. The people who took part in the investigation were healthy volunteers. The people breathed atmospheric air containing 0.04% carbon dioxide for five minutes. They then breathed air containing 2% carbon dioxide for five minutes and then returned to breathing atmospheric air for a further five minutes. The results are shown in . –20 –10 depth of breathing rate of breathing key: 0.04% CO2 2% CO2 0.04% CO2 time / minutes percentage change in rate and depth of breathing Describe the effects of changing the carbon dioxide concentration of the air on the rate and depth of breathing, as shown in . Complete the sentences by writing the appropriate word or phrase in the spaces provided. During physical activity the carbon dioxide concentration in the blood increases. The reason for this is an increase in the rate of that occurs in the in muscle cells. The increase in the concentration of carbon dioxide in the blood is detected by the , which increases the rate and depth of breathing so that carbon dioxide can be from the body. This is important because carbon dioxide is a substance and can cause harm if it accumulates.
0610_s21_qp_43
THEORY
2021
Paper 4, Variant 3
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Table 2.1 shows the percentage of haemoglobin that is inactivated by carbon monoxide present in the blood of taxi drivers in a city. Table 2.1 city taxi drivers percentage of haemoglobin inactivated by carbon monoxide smokers 5.7 day time drivers non-smokers 2.3 smokers 4.4 night time drivers non-smokers 1.0 For Examiner's Use The carbon monoxide in the blood of these taxi drivers comes from two sources. One source is from vehicle exhaust fumes. Name the other source of carbon monoxide that may be inhaled by drivers. Using data from Table 2.1, suggest which of these two sources contributes most to the inactivation of the haemoglobin. Explain your choice. source explanation Calculate the difference in the percentage of haemoglobin inactivated by carbon monoxide in day and night time taxi drivers and suggest a reason for the difference. difference reason Name two other harmful components of cigarette smoke, apart from carbon monoxide. For each, describe an effect it can have on the body of a person who smokes. 1. component effect 2. component effect Suggest a possible effect that might happen to the fetus of a pregnant woman who smokes.
0610_w08_qp_2
THEORY
2008
Paper 2, Variant 0
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Questions Discovered
291