Final answer:
Lions obtain their energy by acting as apex predators, consuming prey that has ingested plants, the primary producers, which originally harnessed the sun's energy through photosynthesis. This is how energy flows through an ecosystem, from sunlight to producers and ultimately to top predators like lions.
Step-by-step explanation:
Lions obtain the energy they need to sustain life through predator-prey relationships by hunting and consuming prey. Predation involves a predator, like the lion, consuming another species, which serves as the prey. Since lions are carnivores, they gain energy by eating either primary consumers (herbivores) or other consumers that have already consumed producers (like plants) which converted light energy to chemical energy through photosynthesis.
In the food chain, energy transfers from the sun to producers and then to consumers. A lion, being an apex predator, is at the top of this energy transfer chain, acquiring energy indirectly from the sun by eating animals which have fed on plants or other herbivores. They embody the concept of energy flow in an ecosystem, transferring energy from one trophic level to another, ultimately tracing back to solar energy captured by primary producers.