Which compound serves as an energy reserve in plants like sweet potatoes?

Starch is the primary energy reserve in plants, including sweet potatoes. It is a polysaccharide made up of numerous glucose units linked together, which allows it to store energy efficiently. When plants produce glucose during photosynthesis, they convert the excess glucose into starch for long-term energy storage. This stored energy can later be broken down into glucose when needed, especially during periods when photosynthesis is not occurring, such as at night or during unfavorable conditions.

In plants like sweet potatoes, starch accumulation allows them to maintain energy balance and support growth and development over time. It is easily digestible by both the plant and herbivores, which utilize it as an important energy source.

The other options, such as glycogen, sucrose, and glucose, do not serve as primary energy reserves in plants. Glycogen is a storage form of glucose in animals, while sucrose is a transport form of sugar in plants and is used for energy during growth rather than as a storage substance. Glucose, while it is the simplest form of carbohydrate and used immediately for energy, is not stored in significant amounts in a form suitable for long-term storage like starch.