NEET BIOLOGY

Detailed explanation-1: -A blue-black color results if starch is present. If starch amylose is not present, then the color will stay orange or yellow.

Detailed explanation-2: -The starch test. Many different food groups contain a carbohydrate known as starch. Using an iodine solution, you can test for the presence of starch. When starch is present, the iodine changes from brown to blue-black or purple.

Detailed explanation-3: -Iodine Solution is used to test the presence of starch.

Detailed explanation-4: -Iodine does not react with other carbohydrates that are not coiled, and remains yellowish brown. Therefore, a bluish black color is a positive test for starch, and a yellowish brown color (i.e., no color change) is a negative test for starch.

Detailed explanation-5: -If the solution contains starch, the iodine turns into blue/black color. The positive iodine result indicates the presence of starch, in which the color gets changed from violet to black. The negative iodine result indicates the absence of starch in a solution, which shows yellow color.