Final answer:
A food web illustrates how energy flows through an ecosystem from producers to consumers and decomposers, with the latter recycling nutrients. Energy transfers are limited to a few levels to maintain efficiency and balance within the ecosystem.
Step-by-step explanation:
A food web in an ecosystem demonstrates how energy is transferred among various organisms, helping to maintain the balance of nature. At the base of a food web are producers, such as plants or phytoplankton, that convert sunlight into energy through photosynthesis. This energy is then passed on to consumers, which include herbivores, omnivores, and carnivores. Herbivores, such as krill in an ocean ecosystem, consume producers and are considered primary consumers. Carnivores, which may include fish and sharks, act as higher-level consumers that prey on other organisms, while at the same time being potential prey to others such as larger predators.
Decomposers, such as bacteria and fungi, play a critical role by breaking down dead and decaying matter, returning nutrients back into the ecosystem, and completing the energy cycle. Energy transfer through a food chain, which is part of a larger food web, is typically limited to 3 or 4 levels to ensure efficiency.