Investigating the need for chlorophyll in photosynthesis

Procedure

  • Destarch a variegated plant – partly green and partly white.
  • Make a drawing of the leaf.
  • Place the plant in bright light for several hours.
  • Test the leaf for starch using the 4-step starch test.
  • Make another drawing of the leaf. In this drawing show the areas of the leaf that tested positive and those that tested negative for starch.
Starch test for chlorophyll

Results

Only the areas that contained chlorophyll (the green parts) will photosynthesise and therefore test positive for starch, showing that chlorophyll is necessary for photosynthesis.