CAIE A Level Biology 9700 · Cell membranes and transport
In the immune system, macrophages must distinguish between 'self' cells and foreign cells. This ability relies on glycoproteins present in the cell surface membrane of the macrophage. Explain how the structure and arrangement of glycoproteins in the cell surface membrane enable cell recognition.
4 marks, so the mark scheme is looking for about 4 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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