Which kingdom includes organisms that must eat other organisms for food?

• A. Animals
• B. Plants
• C. Fungi
• D. Producers

Answer: (A)

Organisms obtain energy in two main ways: making their own food (autotrophs) or consuming other organisms (heterotrophs). Those that must eat other organisms are animals, since they rely on ingesting biomass and then digesting it to get energy and building blocks. Plants and other producers synthesize their own sugars through photosynthesis, so they don’t need to eat. Fungi are heterotrophs as well, but they feed by secreting enzymes and absorbing nutrients from their surroundings rather than by ingesting food, so their feeding method differs from animals. So the group that fits the idea of needing to eat other organisms for food is the animals.