Gas excahnge IB DIPLOMA BIOLOGY Respiratory system 6.4 GAS EXCHANGE – MCQ September 5, 2020 admin 2 Comments Gas Exchange, IBDP Biology Which type of cell is specialized to facilitate gas exchange? Type I pneumocytesType II pneumocytes. Internal intercostal muscle fibresExternal intercostal muscle fibres2. Where does gas exchange occur in the lungs?In type I pneumocytesIn the bronchiolesIn the veins surrounding the alveoliIn the surfactants3. The graph shows the ventilation rate and the oxygen consumption of a subject before, during and after a period of exercise. Which could be a reason for the oxygen consumption to remain high for some time after the end of the period of exercise?Epinephrine keeps the ventilation rate high.Part of the exercise was done using anaerobic respiration.A low ventilation rate keeps the consumption high.More ATP is necessary for cross bridge formation while muscles cool down.4. What is the purpose of pulmonary surfactant?Promotes capillary growthDecreases surface tensionAdheres alveoli and capillariesStretches the inside surface of the alveoli5. Which conditions are correct for inspiration? ABCD6. What changes take place in the thorax during inhalation? ABCD7. The image shows a section of the human respiratory system. Which letter identifies a bronchiole? ABCD8. What muscle actions cause air to be expelled from the lungs?Internal intercostal muscles relax and diaphragm contractsExternal intercostal muscles contract and abdominal wall muscles contractExternal intercostal muscles contract and diaphragm relaxesInternal intercostal muscles contract and abdominal wall muscles contract9. What changes occur in the thorax of a mammal when the external intercostal muscles and diaphragm muscles contract?Pressure increases and volume decreases.Pressure and volume both increase.Pressure and volume both decrease. Pressure decreases and volume increases.10. Which statement describes the movements of the rib cage during inhalation of air?External intercostal muscles contract moving the ribs up and outwards.Internal intercostal muscles contract moving the ribs down and inwards.External intercostal muscles relax moving ribs down and inwards.Internal intercostal muscles relax moving ribs up and outwards.11. What is a feature of alveoli?They occur in all animals because they are needed for gas exchange. They have a higher oxygen concentration than air in the atmosphere to increase the rate of diffusion. They have walls that are one cell thick for faster diffusion. They are small so keep the gases inside them more concentrated12. The diagram shows the ventilation system in humans. What is the function of the structure labelled X? Protect the lungsContract to cause inhalationBecome flatter to move the ribcage upRelax in order to increase the thoracic capacity13. What occurs during the process of ventilation?Contraction of external intercostal muscles raises the ribcage.Relaxation of the abdominal muscles decreases the air volume in the lungs.Contraction of internal intercostal muscles raises the ribcage.Relaxation of the diaphragm decreases the air pressure in the lungs.14. What normally prevents the membranes of the alveoli from sticking together during expiration?The thickness of the single-cell layer of alveoli membranes The secretion of fluids in the inner surface of the alveoli The pressure within the thoracic cavityThe dense net of capillaries covering the alveoli15. What is the function of the structure labelled X? Gas exchangeVentilation RespirationInspiration16. Which of the following features of the alveoli adapt them to gaseous exchange? Single layer of cells II. Film of moisture III. Dense network of capillaries I and II onlyII onlyII and III onlyI, II and III17. What happens to the external and internal intercostal muscles and diaphragm when inhaling? ABCD18. Which muscles contract to cause air to pass into the lungs through the trachea?Internal intercostal muscles and diaphragm Internal intercostal muscles and abdomen wall muscles External intercostal muscles and diaphragm External intercostal muscles and abdomen wall muscles19. What change occurs to the pressure and volume of the lungs when the external intercostal muscles contract?Both pressure and volume increase.Pressure increases and volume decreases.Pressure decreases and volume increases.Both pressure and volume decrease.20. What feature of alveoli adapts them to efficient gas exchange?They have muscles which pump air in and out regularly.Their membranes are more permeable to gases than water.A constant blood supply flows through them.A dense network of capillaries surrounds them.21. Which muscle action is associated with an increase in the volume of the thoracic cavity when breathing in?The diaphragm contracts.The external intercostal muscles relax.The internal intercostal muscles contract.The abdominal muscles contract.