What form does glucose take when stored in plants?

When plants store glucose, they convert it into starch. Starch is a polysaccharide made up of many glucose units linked together. This form is particularly advantageous for plants because it is insoluble in water, which allows for compact storage without affecting the osmotic balance within plant cells. The storage of energy in the form of starch enables plants to retain a reserve of glucose that can be utilized for energy during periods of low light or when photosynthesis cannot occur, such as at night.

In contrast, fructose and sucrose are forms of sugar that are involved in different metabolic processes. Fructose is a monosaccharide, and sucrose is a disaccharide composed of glucose and fructose, primarily involved in transport rather than long-term energy storage in plants. Cellulose, while also made from glucose, serves a structural role in plant cell walls rather than being a storage form of energy. Therefore, starch is the correct answer as it is specifically the stored form of glucose in plants.