The cells of the green part of the leaf contain chloroplasts containing chlorophyll. Sugar is formed in them, and then starch. In the cells of the white border of the leaf bordered geranium, there are no chloroplasts and, accordingly, there is no chlorophyll. Starch is not formed in these cells. And iodine turns blue only in the presence of starch.
One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.