Glucose is the main product of photosynthesis. With reference to this statement, answer the following questions.
(a) Leaves are found to possess very less or no glucose in them when they are tested. Justify this contradiction.
(b) In which form is carbohydrate translocated through phloem tissue in the plant? Why?

Explanation

(a) Glucose cannot store energy for long time. Therefore, as soon as it is synthesized, a part of it is utilized for respiration. The rest of it is immediately converted into sucrose, starch or cellulose. Therefore, glucose is rarely found in the leaves in appreciable proportions.
(b) Carbohydrate is translocted in the plant in the form of sucrose. More over, food cannot be translocated in the form of glucose as it carries less amount of energy and it is less stable and may react with other substances on the way. Starch is insoluble in water and cannot be carried in cell sap.