What concept is illustrated by the relationships and interactions among living organisms in an ecosystem?

The concept illustrated by the relationships and interactions among living organisms in an ecosystem is best described by ecological networks. Ecological networks encompass the various connections and interactions between different species, including predator-prey dynamics, symbiotic relationships, and competition for resources. These interactions help to illustrate the complexity of ecosystems and the interdependence of species within them.

In contrast, biomes refer to large geographical areas characterized by similar climates and ecosystems but do not specifically address the interrelationships among organisms. Food chains, while demonstrating how energy flows through an ecosystem by showing who eats whom, are a more simplified representation and do not capture the full complexity of interactions present in an ecological network. Ecology, as a broader field, studies these interactions, but the term "ecological networks" specifically focuses on the relationships among organisms within that framework.