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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 in the lungs are where oxygen enters the blood, and carbon dioxide is expelled. The large surface area provided by numerous alveoli facilitates efficient gas exchange.
Step 2
Explain how emphysema would affect the amount of oxygen carried in the bloodstream.
Answer
Emphysema damages the alveoli, reducing their number and causing them to lose elasticity. This leads to a decreased surface area for gas exchange, resulting in less oxygen being absorbed into the bloodstream. Consequently, individuals with emphysema may experience lower oxygen levels, leading to shortness of breath and reduced physical capacity.