Final answer:
Organisms that must eat to obtain energy are called heterotrophs. They rely on consuming other organisms or organic matter for energy.
Step-by-step explanation:
Organisms that must eat to obtain energy are called heterotrophs. Heterotrophs are unable to produce their own food through photosynthesis, so they rely on consuming other organisms or organic matter for energy. Examples of heterotrophs include animals, fungi, and many bacteria. These organisms obtain energy by breaking down molecules from their food through processes like digestion and cellular respiration.
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