CAIE A Level Biology 9700 · Transport in mammals
During vigorous exercise, the concentration of carbon dioxide in actively contracting muscle cells rises. Explain the mechanism by which this increased CO2 affects the transport of oxygen by haemoglobin, and state why this is beneficial to the muscle.
7 marks, so the mark scheme is looking for about 7 separate creditworthy points. Making the same point twice in different words earns it once.
Explain means: Give the reasons or the mechanism: why or how something happens. Link each point to the next with because, so or which means. A list of facts with no links usually loses the reasoning marks.
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