Fig. 2.1 is a graph showing the effect of carbon dioxide concentration on the rate of photosynthesis: the rate rises steadily from A to B, then stays level from B to C.

1. aDescribe and explain the shape of the graph from A to B. [3]
2. bDescribe and explain the shape of the graph from B to C. [2]
3. cLight energy is converted by chlorophyll into a form that plant cells can use. State the form into which light energy is converted. [1]

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