3. Gas Exchange

Identify the structure labelled A in the diagram

• Alveolus

• Bronchus

• Terminal bronchiole

• Capillary

Which of the labels is pointing to the plasma?

• B

• C

• D

• E

Which of the features allows the oxygen to dissolve before diffusing across the alveolar wall?

• B

• C

• D

• E

What is the percentage of oxygen in inspired air?

• 0.4

• 4

• 16

• 21

What is the percentage of carbon dioxide in expired air?

• 0.4

• 4

• 16

• 21

Which alveolus adaptation maximises gaseous exchange by maintaining a concentration gradient?

• Large surface area

• Moist lining

• Rich blood supply

• Thin wall

Which letter show the diffusion of carbon dioxide during gaseous exchange?

• X

• Y

Which gas within inspired air has a concentration of 78%?

• Carbon dioxide

• Nitrogen

• Oxygen

• Water vapour

What chemical is used to detect the presence of carbon dioxide?

• Acid

• Alkali

• Lime water

• Water

In which flask would the lime water be more cloudy?

• A

• B