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DP IB Biology: HL

Topic Questions

Home / IB / Biology: HL / DP / Topic Questions / 6. Human Physiology / 6.4 Gas Exchange / Structured Questions: Paper 2


6.4 Gas Exchange

Question 1a

Marks: 3
a)

Describe the pathway taken by a molecule of oxygen from the outside air to the blood of a human.

[3 marks]

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    Key Concepts
    Air Pathway

    Question 1b

    Marks: 3
    b)

    Premature babies can suffer from a deficiency of a substance referred to here as substance X. This can lead to a condition known as respiratory distress syndrome (RDS). The image below shows the possible appearance of the lung tissue of an RDS patient (left) and the appearance of normal lung tissue (right).

    6d47aa2e-db32-44ac-a1cc-73082aed8c40

    Image courtesy of Atlas of Pulmonary Pathology, licensed under the Creative Commons Attribution-ShareAlike 2.0 Generic license, and adapted and redistributed under conditions found at https://creativecommons.org/licenses/by-sa/2.0/ 

    i)

    Suggest the identity of substance X.

    [1 mark]

    ii)
    Explain the appearance of the RDS lung tissue in the image above.

    [2 marks]

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      Key Concepts
      Type II Pneumocytes

      Question 1c

      Marks: 4
      c)

      RDS can be treated by the administration of an alternative form of substance X to the lungs. The graph below shows the effect of different variations of substance X on the lung volume of rabbits at different pressures. The variations include substance X isolated from sheep lungs, as well as synthetic versions of substance X that contain its separate lipid and protein components. Note that cm H2O is a unit of pressure.~Yu4loNm_h-1c

      Use the information provided to explain why each of the following statements is incorrect:

      i)

      Substance X is essential for lung expansion.

      [1 mark]

      ii)

      Phospholipids are the active component of substance X.

      [1 mark]

      iii)

      Substance X from sheep is the most effective treatment for RDS in premature babies.

      [2 marks]

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        Key Concepts
        Type II Pneumocytes

        Question 1d

        Marks: 2
        d)

        The form of substance X produced in mammalian lungs contains proteins known as SP-A and SP-D, which are known to be involved with the activation of phagocytes.

        Suggest, with a reason, a symptom that would result from a deficiency of SP-A and SP-D proteins.

        [2 marks]

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          Question 2a

          Marks: 2
          a)

          A study was carried out that looked at the movement of the diaphragm during normal breathing. The graph below shows the diaphragm movement in a healthy 55-year-old male.Wis-RR3o_h-2a

          Calculate the breathing rate of the individual shown in the graph.
          [2 marks]
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            Question 2b

            Marks: 3

            b)

            i)
            Identify the ventilation processes occurring at the stages marked X and Y.

            [1 mark]

            ii)

            For the stage marked Y on the graph, name a muscle other than the diaphragm involved at this stage and identify its state. 

            [2 marks]

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              Question 2c

              Marks: 4
              c)
              The graph below shows the results of another participant in the study. This individual is a 57-year-old male with emphysema.LmaqJ_7a_h-2c

              i)

              Contrast the graph shown here with the graph in part a).

              [2 marks]

              ii)

              Suggest an explanation for the differences between the graphs.

              [2 marks]

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                Question 2d

                Marks: 2
                d)

                Events such as surgical trauma or nerve degeneration can lead to weakness or even paralysis of the diaphragm.

                Suggest the effect that this would have on ventilation

                [2 marks]

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                  Question 3a

                  Marks: 2
                  a)

                  The graphs below show smoking prevalence and lung cancer deaths in men and women in the UK between 1950 - 2000.

                  tNrm~Qxv_h-3a

                  Calculate the percentage decrease in smoking prevalence between 1950 - 1990 for:

                  i)

                  Men

                  ii)
                  Women
                  [2 marks]

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                    Key Concepts
                    Cancer

                    Question 3b

                    Marks: 3
                    b)

                    Compare and contrast the trends in smoking prevalence and lung cancer deaths between men and women in the graphs shown in part a).

                    [3 marks]

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                      Key Concepts
                      Cancer

                      Question 3c

                      Marks: 3
                      c)

                      A student looked at the graphs in part a) and concluded that cigarette smoking causes lung cancer.

                      Evaluate this conclusion from the graphs shown.
                      [3 marks]
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                        Key Concepts
                        Cancer

                        Question 3d

                        Marks: 3
                        d)

                        Data from other studies provide support for the student's conclusion in part c) and scientists now accept that smoking can cause lung cancer.

                        Explain the link between smoking and lung cancer.
                        [3 marks]
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                          Key Concepts
                          Cancer
                          Tumour Formation

                          Question 4a

                          Marks: 3
                          a)

                          Certain types of lung disease can be categorised as either obstructive or restrictive. The effect of obstructive and restrictive lung diseases on ventilation can be seen in the graph below, where:

                          • Tidal volume (TV) = the volume of air breathed in and out with each normal breath
                          • Inspiratory reserve volume (IRV) = the additional volume of air that can be drawn into the lungs during a large inward breath
                          • Expiratory reserve volume (ERV) = the additional volume of air that can be expelled from the lungs during forced expiration
                          • Residual volume (RV) = the volume of air that remains in the lungs after forced expiration0lbCHPN6_h-4a

                          Compare and contrast the effects of obstructive and restrictive lung disease.

                          [3 marks]

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                            Question 4b

                            Marks: 3
                            b)

                            An example of an obstructive lung disease is emphysema.

                            Suggest how emphysema causes the features of an obstructive lung disease shown in the graph in part a).

                            [3 marks]

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                              Key Concepts
                              Emphysema

                              Question 4c

                              Marks: 3
                              c)
                              Explain why sufferers of both obstructive and restrictive lung disease find exercise difficult.
                              [3 marks]
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                                Question 4d

                                Marks: 2
                                d)
                                Use the graph in part a) to suggest what might be happening to the lungs in a restrictive lung disease.
                                [2 marks]
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                                  Question 5a

                                  Marks: 3

                                  One mark is available for clarity of communication throughout this question.

                                  a)
                                  Outline the need for a ventilation system in mammals.

                                  [3 marks]

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                                    Question 5b

                                    Marks: 6
                                    b)

                                    Draw an annotated diagram to explain the process of inspiration.

                                    [6 marks]

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                                      Question 5c

                                      Marks: 6
                                      c)

                                      Explain how the lungs are adapted to their function.

                                      [6 marks]

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