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Figure 10 shows alveoli from a lung - Edexcel - GCSE Biology - Question 9 - 2019 - Paper 1
Question 9
Figure 10 shows alveoli from a lung. (a) (i) Explain why these alveoli have the internal structure shown in Figure 10. (ii) How does oxygen move across the alveo... show full transcript
Worked Solution & Example Answer:Figure 10 shows alveoli from a lung - Edexcel - GCSE Biology - Question 9 - 2019 - Paper 1
Step 1
Explain why these alveoli have the internal structure shown in Figure 10.
Answer
The internal structure of the alveoli is designed to maximize gas exchange. Firstly, the alveoli have a large surface area due to their numerous small sacs, which allows for more oxygen to diffuse into the blood. Secondly, they consist of thin walls (only one cell thick), which minimizes the distance that gases must travel, thereby facilitating faster diffusion. Additionally, the presence of a moist lining helps dissolve gases, promoting efficient exchange.
Step 2