Which of the following is a characteristic of glycogen?

Glycogen is a polysaccharide that serves as a key energy storage molecule primarily in animals. One of its defining characteristics is its structure, which allows for the rapid mobilization of glucose units when energy is needed. This rapid mobilization is facilitated by glycogen's branched structure, allowing for quick access to glucose during periods of high energy demand, such as exercise or fasting. In contrast, glycogen is less commonly utilized as an energy source in plants, where starch is the primary storage polysaccharide. Additionally, while glycogen does store glucose in a solid or semi-solid form, it is primarily a polymer rather than a direct solid form of glucose and is not more abundant in plants than in animals, making its function in glucose mobilization in animals the most accurate and relevant characteristic.