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WAEC Biology 2003 Question 28

Question 28

Photosynthesis and Plant Nutrition

In the test for starch, the leaf is first placed in boiling water to

  1. A.remove the chlorophyll
  2. B.dissolve the waxy cuticle
  3. C.kill and make the leaf permeable
  4. D.turn it blue-black
Show the answer and explanation

Answer: C (kill and make the leaf permeable)

Explanation

Boiling kills the cells, stops their reactions and makes the membranes permeable so alcohol and iodine can get in. Chlorophyll is removed later by alcohol.