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DP IB Biology: SL

Topic Questions

Home / IB / Biology: SL / DP / Topic Questions / 6. Human Physiology / 6.4 Gas Exchange / Multiple Choice: Paper 1


6.4 Gas Exchange

Question 1

Marks: 1

Which row of the table describes the best overall conditions for gas exchange in the lungs?

  Surface Area Diffusion Pathway Concentration Gradient
A. Large Long Steep
B. Large Short Steep
C. Large Short Shallow
D. Small Short Shallow
    Choose your answer
      
    Key Concepts
    Ventilation

    Question 2

    Marks: 1

    Which row of the table shows the events of inspiration in the correct sequence?

      1 2 3 4
    A. Diaphragm and external intercostal muscles contract Volume of thorax increases Thorax pressure drops Air is drawn into the lungs down its pressure gradient
    B. Thorax expands Thorax pressure drops Diaphragm and external intercostal muscles contract Volume of thorax increases
    C. Air is drawn into the lungs down its pressure gradient Diaphragm and external intercostal muscles contract Thorax pressure drops Volume of thorax increases
    D. Thorax pressure drops Volume of thorax increases Thorax expands Air is drawn into the lungs down its pressure gradient
      Choose your answer
        

      Question 3

      Marks: 1

      Which of the following is a feature of forced expiration?

      • The diaphragm contracts.

      • The thorax undergoes a drop in pressure. 

      • The internal intercostal muscles contract. 

      • The external intercostal muscles contract.

      Choose your answer
        

      Question 4

      Marks: 1

      Which aspects of ventilation are assisted by the solution secreted by type II pneumocytes?

      1. Dissolving of oxygen gas.

      2. Recoil of alveolar walls during expiration.

      3. Preventing alveoli from collapsing.

      4. Diffusion of carbon dioxide gas into the alveoli.

      • I, II, and IV only.

      • I and IV only.

      • I, III, and IV only.

      • I and III only.

      Choose your answer
        

      Question 5

      Marks: 1

      Patients with emphysema are often prescribed oxygen cylinders to breathe from. The oxygen concentration in a cylinder is around 90%, compared to 21% in atmospheric air. 

      How does breathing concentrated oxygen increase the effectiveness of the lungs?

      • Increases concentration gradient.

      • Assists expiration of stale air. 

      • Makes breathing easier.

      • Decreases diffusion pathway. 

      Choose your answer
        
      Key Concepts
      Emphysema
      Ventilation