Question

observations in the experiment test for the presence of starch

Answer 1

Starch is the most common carbohydrate in the human diet and is contained in many staple foods. The major sources of starch intake worldwide are cereals (rice, wheat, and maize) and root vegetables (potatoes and cassava). We can use iodine solution to test for the presence of starch.  Add one drop of (brown) iodine solution on the tile and look for a colour change. A blue-black colour indicates the presence of starch.