Concept:Glucose is soluble, but starch is insoluble; plants convert glucose to starch to prevent osmotic damage in leaf cells.
Explanation:During the day, photosynthesis produces glucose in the leaf.
This glucose is soluble and dissolves in the cell sap.
If it remained dissolved, the cell sap concentration would become too high.
Water would then enter the leaf cells excessively from the surroundings, causing osmotic problems.
By converting glucose into starch, which is insoluble, the leaf avoids this water imbalance.
At the same time, starch serves as a safe, temporary storage product that can be converted back to glucose later when needed.
Therefore, the principal reason for this conversion is to protect the leaf from osmotic difficulties, not merely to store starch or use up glucose.
Answer:B. prevents osmotic problems