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A-LevelBiologyGas exchange9700/12 · Oct/Nov 2021 · Q321 Mark

What explains how the maximum volume of oxygen is taken up as blood passes through the capillaries of the lungs?

AEach haemoglobin molecule can temporarily bind to four oxygen atoms.
BThe dissociation of carbon dioxide from carboxyhaemoglobin allows more haemoglobin to be available for binding oxygen.
CThe binding of the first oxygen molecule to haemoglobin decreases the affinity of haemoglobin for binding other oxygen molecules.
DOxyhaemoglobin formation increases the ability of red blood cells to transport oxygen.

✓ Correct answer

D: Oxyhaemoglobin formation increases the ability of red blood cells to transport oxygen.

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About this question

Topic
Gas exchange, A-Level Biology (syllabus 9700). Multiple choice, 1 mark.
Source
A-Level Biology, Oct/Nov 2021 Paper 1 Variant 2, question 32.

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