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Figure 3 shows a pair of human lungs - Edexcel - GCSE Biology Combined Science - Question 3 - 2016 - Paper 1
Question 3
Figure 3 shows a pair of human lungs. (a) (i) Where does gas exchange take place in the lungs? A alveolus B bronchus C bronchiole D trachea A person had emphysema... show full transcript
Worked Solution & Example Answer:Figure 3 shows a pair of human lungs - Edexcel - GCSE Biology Combined Science - Question 3 - 2016 - Paper 1
Step 1
Where does gas exchange take place in the lungs?
Answer
Gas exchange primarily takes place in the alveoli. These tiny air sacs are lined with a thin membrane that facilitates the diffusion of oxygen into the blood and carbon dioxide out of the blood. The large surface area provided by numerous alveoli enhances this process.
Step 2
Explain how emphysema would affect the amount of oxygen carried in the bloodstream.
Answer
Emphysema damages the alveolar walls, leading to a reduction in the total number of alveoli. This decreases the surface area available for gas exchange, which can result in lower levels of oxygen entering the bloodstream. Consequently, the oxygen saturation in the blood may decrease, leading to various health issues, including shortness of breath and fatigue, as the body struggles to meet its oxygen demands.