Amy is asked to determine the chemical composition of an unknown liquid sample. She determines that the sample is negative for protein, simple sugars, and lipids. However, someone else has used up all of the iodine reagent. Which scenario would allow Amy to test the unknown sample for the presence of starch

Amy can apply the Tyndall Beam effect, by shining a beam of light through the sample solution.

Explanation:

The chemical test for starch is add iodine solution to the tested sample which is yellow/brown and observe the color change to blue/black color. However, the physical test to distinguish simple sugars from starch is the shine a beam of light through the sample solution. Because that sample solution contained no simple sugars, then the presence of starch in the solution will be indicated by dispersal of light because the large starch molecules are enough to affect the light.