A small piece of black paper was folded in half and use to cover part of the top and bottom portions of a leaf on the living geranium plant. After the plant was kept in sunlight for several days the paper was removed the leaf was then boiled in alcohol to remove chlorophyll and placed in Lugol's iodine solution, which turns blue- black in the presence of starch. Only the part of the leaf had not been covered turn black-blue.This investigation was most likely testing the hypothesis that