Maharashtra State PSC Model Paper 4

The correct answer is Blue-black.

• A star-shaped figure was cut in the black paper strip used for covering the leaf of a destarched plant.
  • It was used for demonstrating that light is necessary for photosynthesis.
  • At the end of the experiment when the leaf was tested for starch with iodine, the star-shaped figure on the leaf was found to be blue-black in colour.
  • It was exposed to light and hence, starch was formed in this part of the leaf.