The answer here is THE LEAF IN FLASK B WILL NOT GET CARBON DIOXIDE TO MAKE GLUCOSE. In order to carry out photosynthesis, plant needs several ingredients. It needs chlorophyll, the green coloring pigment in plants, sunlight, water and carbon dioxide. To nurture growth, plant needs a favorable medium (usually good soil but there are also those that can grow attached to another plant and those called aerial plants) and nutrients. Carbon dioxide is one of the most abundant gases in the atmosphere. It plays an important role in both plant (photosynthesis) and animal (respiration) processes. In photosynthesis, green plants convert carbon dioxide and water into food compounds such as glucose and water. The oxygen released during photosynthesis is needed by animals, human also, for respiration. Potassium hydroxide, on the other hand, is an inorganic solid compound which absorbs carbon dioxide. During experiments, plants placed inside a solution with potassium hydroxide will test negative in starch test. Absence of starch is attributed to the absorption of carbon dioxide by potassium hydroxide. Photosynthesis did not happen because of the absence of one of its ingredients which is carbon dioxide,hence absence of one of the end products, starch.
