Final answer:
The energy in food originally comes from the process of photosynthesis. Glucose, a type of sugar, is a source of energy that is stored in plants and is then transferred to animals when they consume plants or other animals.
Step-by-step explanation:
The energy in food originally comes from the process of photosynthesis. Photosynthesis is a biological process carried out by plants, algae, and some bacteria, in which they convert sunlight, water, and carbon dioxide into glucose and oxygen. Glucose, a type of sugar, is a source of energy that is stored in plants and is then transferred to animals when they consume plants or other animals.