Final answer:
Energy is acquired in three ways: photosynthesis, chemosynthesis, and consumption/digestion of other organisms. Animals acquire energy through the consumption of other organisms in food chains.
Step-by-step explanation:
Energy is acquired by living things in three ways: photosynthesis, chemosynthesis, and the consumption and digestion of other living or previously living organisms by heterotrophs. Photosynthesis is the process by which plants convert sunlight into glucose, which is then used by plants and animals for energy. Cellular respiration is the process by which organisms break down glucose and release energy. Animals acquire energy by consuming other organisms through the food chain, where energy is transferred from one organism to another.