Answer:
Starch
Step-by-step explanation:
The iodine is a dark blue colour in solid state and in water solution it is yellow-brown. When this liquid iodine is added on a piece of bread or potato slices, the colour of bread and potato becomes blue. This also uses as an indicator of starch present in a substance. Iodine is also used in the green leaf to know the product of photosynthesis is carbohydrates. The colour of iodine solution changes from yellow-brown in the presence of starch to dark blue.