A leaf that has been kept in the dark for 48 hours is tested for starch with iodine. What result is expected?
Answer and explanation
Correct answer: B. The leaf stays brown
- Step 1: Without light there is no photosynthesis, so the starch is used up and iodine remains brown. Answer: The leaf stays brown. Why not the others: The leaf turns blue-black: No starch is made without light. The leaf turns brick red: Brick red is the result of Benedict's test. The leaf turns green: Iodine does not make leaves green.
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