A student puts a potted plant in the dark for 48 hours, then covers part of one leaf with foil and leaves the plant in sunlight for 6 hours. The leaf is then tested for starch.

1. aWhy was the plant first kept in the dark? [1]
2. bDescribe how the leaf is tested for starch. [3]
3. cState and explain the results for the covered and uncovered parts. [2]

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